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Claude Opus 5.5

471 points3 hoursanthropic.com
sailingparrot2 hours ago

> Claude Opus 5.5 is our first release since we called for pacing the frontier.

Interesting how the very first line is used to remind the reader of their call to pace the frontier just last week, and everything else after that line is to demonstrate with very specific numbers how they absolutely are not pacing.

mukmuk2 hours ago

“Pacing the frontier” sounds smarmy and weird, like the phrase was generated by Claude itself

DiggyJohnson2 hours ago

I really don't think it's productive for internet forums to constantly be criticizing language choice when the meaning is clear. Better to respond to the substance of the issue than word choice.

Edit: In response to the initial replies. To me it clearly means "releasing frontier models at any pace less than as fast as possible". It implies relative restraint compared to the previous state and without stating the degree of restraint.

mpalczewski2 hours ago

The meaning isn't clear at all. So open for interpretation that it is meaningless. That's the whole fucking point. For all I know they are "pacing the frontier", or not. The fact that there's no meaning to it let's you know that it was a pointless waste of tokens and attention.

glenstein1 hour ago

I think it's perfectly clear. It means improvements shouldn't simply advance as fast as possible and more specifically, it's a reference to a past statement of theirs to that effect. At that level of generality it's as clear as it needs to be.

I would say the burden is on you to explain why an offhand reference to a previous press release in an executive summary is a context where it's reasonable to expect it to settle the question to the degree of detail you're demanding.

post-it2 hours ago

Is the meaning clear? Nobody would use "pacing" in this way. I only know what it means because I've seen previous press releases; if someone told me they wanted to pace the frontier I would have no idea what they mean.

I'm on the fence about calling out AI-isms but I think it's definitely worthwhile to call out ones that actually don't make sense.

+1
sigmar2 hours ago
+6
johnisgood2 hours ago
tetha1 hour ago

I'm on the fence there.

To pace something is a fairly regular formulation in racing, running, cycling, most sports. You can "pace yourself to reach the festival by bike in about three hours to not gas out". This means to control your speed and time investment intentionally so you don't run out of energy or steam and run into leg cramps before your goal. We can "pace a rollout slowly to burn out risks", or "increase the pace of a rollout due to adverse factors".

But I have noted a point to simplify my vocabulary at work to optimize the audience capable of understanding. So I rather defer the delving into deep dark corners of the dictionary derived from devouring literature to a simple intro or outro, and people find it funny, especially if the rest is easy to read. Claude on the other hand does not do that.

derac2 hours ago

In racing a pace car is a car that leads the pack and sets the pace, for instance.

neo_doom2 hours ago

I suppose it depends on your life experiences. In running, someone who paces the group or a pace car is meant to keep the pack progressing at a constant, predictable speed. So in that way, it makes sense to me

qlte2 hours ago

Yeah, when I first saw it referenced I assumed it was from something Dario wrote previously and was now disavowing, meaning "keeping up with the frontier" (i.e. racing forward from behind to match pace). Like from back when Anthropic was founded to promise they'd quickly catch up with OpenAI or something.

squidbeak2 hours ago

> Nobody would use "pacing" in this way.

A world exists beyond your vocabulary, post it. Apparently, quite a big world.

Leynos1 hour ago

Think of a pacer car in motorsport

+1
arw0n2 hours ago
staindk1 hour ago

Think most people are aware of the phrase "pace yourself".

+2
browningstreet2 hours ago
kelnos56 minutes ago

My first thought from "pacing the frontier" is someone standing out in the Old West, nervously walking back and forth.

It's a weird phrase. Not sure why there are so many people who feel the need to defend it with such passion.

icedchai46 minutes ago

It smells of corporate speak, a total nonsense phrase. Even by your own admission, it is essentially meaningless. If I release a model an hour late, I'm "pacing the frontier."

vmnb2 hours ago

people are here because they are sick of being productive

kadushka2 hours ago

We are being productive here!

+1
vasco2 hours ago
lukewarm70754 minutes ago

language creates reality.

"there is nothing outside the text" - Jacques Derrida

patcon2 hours ago

Agreed. This feels like pointless navel-gazing and a strange new language policing, and not something I look forward to. It's tiring and it lacks curiosity (e.g. "what's behind the affinity for the words elevated from wherever it is they come from?").

Imho people should just respond to actual ideas instead of constantly engaging in the second-order critique of how the language may or may not have been created.

It strikes me as the intellectual equivalent of "gossip" to be constantly engaging in second-order commentary on words. Of course gossip has its place and purpose, but if we seem to only let our minds live at that level, we're not moving between all the required scales of thinking that are required of this moment imho <3

+1
platinumrad1 hour ago
lxgr1 hour ago

You must be pretty new to (not just) online discussions if you consider language policing to be a new phenomenon :)

Personally I consider it equally valid for people to publicly express annoyance with somebody's choice of words and for everybody to completely ignore that annoyance.

isoprophlex2 hours ago

You're really verbing the noun on the discourse here, belt and suspenders-style

DiggyJohnson1 hour ago

what?

OJFord1 hour ago

> I really don't think it's productive for internet forums to constantly be criticizing language choice when the meaning is clear. Better to respond to the substance of the issue than word choice.

Wtf is the meaning? Means absolutely nothing to me having not seen the apparent announcement last week introducing the obscure term.

rythmshifter1 hour ago

I don't disagree with you, but I have to remind you

sir, this is a hacker news thread

Ar-Curunir2 hours ago

You’re acting like people are being grammar nazis when Claude and the ilk are actively making a mockery of language.

DiggyJohnson1 hour ago

What? How am I doing that. Claude writing style and the discussion at hand are two entirely separate issues that I haven't conflated at all. How am I "acting like people are being grammar nazis"?

tclancy2 hours ago

It combines the elegance of LinkedIn-speak with the humbleness of desk-bound people who speak in military metaphor.

mpalczewski2 hours ago

good use of AI to generate this.

jrochkind144 minutes ago

I feel like because something about "pacing" a kind of noun like "the frontier", doesn't actually make literal sense, right? You could say "Pace the speed of advancement of the frontier [of most sophiticated AI]", and that's perfectly sensible, but of course that's not as catchy.

It is clear what it means anyway, that's true, it means the left out words, more or less.

And I still find reading these grammatically weird but super catchy slogan-like statements to be really annoying and taxing. People _did_ write and talk like this before LLMs of course -- the LLMs learned it from somewhere -- and it was annoying and taxing to me before too. But the LLMs really specialize in it, and it's everywhere now.

Of course, the more LLM slop we read -- and so much of what we read on the internet and social media of any kind is this now -- the more humans are going to start writing/talking like LLMs. What you read affects how you write of course.

nonethewiser2 hours ago

IDK I think Anthropic is plenty smarmy and weird itself. Sounds like they wrote it.

topbanana2 hours ago

You're right to call that out

Dumblydorr2 hours ago

What specifically is smarmy and weird? Sounds like your own hot take with zero analysis.

They’re limiting frontier model development speed. Others are too. Pacing is the only word here to criticize, and I think it’s fine given the limiting of speed but also increased oversight. I’m not saying they’re fully doing this, but the term is fine.

Do you have a better proposed phrase?

Rebelgecko1 hour ago

I thought pacing is just walking back and forth? So pacing the frontier would be like staying in the same place instead of making progress

lkbm1 hour ago

It is that, but it's also your speed. When running, you typically pick a pace that's slower than your max, so it can be sustained for the full distance.

"Pace yourself" specifically means "slow down".

plaidfuji1 hour ago

“… since we called for a slowdown in AI research

But stating it plainly like this would make the contradiction too obvious.

marton782 hours ago

Sounds like "flatten the curve" and "the hammer and the dance", both coined well before AI.

tclancy2 hours ago

I learned the former from Waylon Jennings and the Dukes of Hazzard.

pvab32 hours ago

except with a good dose of EA and Star Trek added in

palmotea1 hour ago

> “Pacing the frontier” sounds smarmy and weird, like the phrase was generated by Claude itself

Claude says it sounds fine. And Claude is now the judge of the English language style, not you.

gradus_ad2 hours ago

Agreed when I first heard the phrase it sounded odd. Maybe they thought it subtly conveyed they would be setting the pace... But again this is something AI would come up with in its awkwardly post hoc sort of way.

Though tbf corporate-speak and AI-slop are both insufferable in similar ways...

grohan1 hour ago

Quite the load-bearing phrase!

api52 minutes ago

Anthropic is a religious cult that worships Claude, so maybe they're imitating Claudese.

dmazin2 hours ago

It seems like they are. I mean, this is similar in performance to Fable (ish). It seems like more focus on making existing capabilities more accessible.

sailingparrot2 hours ago

Fable 5.1 came out just 21 days ago. Only 3 weeks! And this is 20% relative improvement on terminal bench vs Fable 5.1 at less than half the price, and more human sounding output. does not feel paced to me tbh.

davrosthedalek2 hours ago

Well, I guess it's "fast paced".

jr35922 hours ago

What exactly is "paced" in this context?

+2
sailingparrot2 hours ago
dmix2 hours ago

Fable 5.1 wasn't that much different than Fable 5 though.

cab648bec139cc2 hours ago

Do you guys still believe any of their lies? You are getting trolled for years by now and yet you still believe what they tell you?

supern0va2 hours ago

That's a great point, five minute old account.

sleazebreeze2 hours ago

What do you think is happening?

re-thc2 hours ago

IPO soon

+3
cab648bec139cc2 hours ago
reasonableklout1 hour ago

I mean they are literally getting sued since 3 days ago for trying to coordinate a slowdown, there is a very clear reason why they cannot effectively self-regulate.

the_gipsy2 hours ago

Occam's razor: they couldn't make any more substantial improvements.

dgellow2 hours ago

A razor is a philosophical tool to help decide between options, in the case of Occam it’s a way to decide for something in a situation where multiple options have more or less the same level of plausibility to en your current knowledge. It’s a heuristic to make a “cut”. What are you shaving off?

usewik1 hour ago

The "pacing the frontier" claims that they are slowing down intentionally?

someothherguyy2 hours ago

> Occam's razor: they couldn't make any more substantial improvements.

doesn't sound like a razor at all

bpodgursky2 hours ago

Everyone knows both labs have internal models which outperform the frontier. All releases are to match market parity and demand for spend, the rest of the compute is used for training. It's not worth arguing about this.

nextaccountic2 hours ago

Maybe their internal edge dried up in the last months

tantalor1 hour ago

"pacing the frontier" is code for downgrading your expectations of AGI.

bonesss45 minutes ago

Or, in parallel, the research showing LLMs intelligence will operate on an S-curve, eventually hitting a long valuation deflating plateau, is dead on the money and The Big Guys are trying to delay that inevitability for as many quarters as possible…

Tade043 minutes ago

My hypothesis is that to date they've been increasing benchmark scores via scaling up, but now that low hanging fruit is basically picked.

lukewarm7072 hours ago

the only thing they are pacing is what models the permanent underclass are allowed to have in life.

that, they fully intend to 'pace'.

drnick12 hours ago

With AI tools it's easier than ever to create a business, do research, or build stuff. That's an opportunity for the "underclass," not a curse.

lukewarm70758 minutes ago

an opportunity the underclass will not have.

what anthropic have stolen they intend to keep for themselves.

user39393822 hours ago

Or they’re running into a steep diminishing return slope on R&D vs performance and are using stewardship as a cover.

azan_2 hours ago

Either AI will capture so much value that there will be permanent underclass (and in this case it's extremely capable and extremely dangerous and should be heavily regulated) or it won't be capable enough to displace people into permanent underclass.

Iolaum2 hours ago

They are advertising the regulations they want to enforce in the following sentence, which makes their intentions explicit (ie apply those things made to suit us to our competitors).

mullingitover59 minutes ago

I thought we were all aware that 'pacing the frontier' was a marketing slogan, and the actual intent here was to suspend antitrust laws.

dspillett2 hours ago

When they talk about pacing, they are referring to their dangerous competitors, particularly those evil open-sores and Chinese ones, not their lovely safe models because you can trust them to look after your interests.

What the big players are trying with the current calls to slow things down, is the standard capitalism practise of trying to engineer regulatory capture. TBH I'm surprised those calls are coming so soon - they must be really worried about running out of what little moat that they have.

tencentshill2 hours ago

What an amazing excuse for lower than expected performance! Our models are slow because we're so ethical.

felixgallo1 hour ago

in what way is beating every other frontier model with their own second-tier model, 'lower than expected performance'? Please be specific.

kadushka2 hours ago

This makes perfect sense. There are no real improvements anymore (just benchmaxxing), and they explain it by "pacing the frontier".

qgin1 hour ago

This IS pacing. Nobody said pacing would mean slow.

Pacing is very explicitly about RSI and similar training methods that will accelerate progress beyond our ability to comprehend it.

janpot1 hour ago

"The improvements are underwhelming for a model that, according to previous claims, should have replaced all knowledge work twice by now, but you know, it's just because we're pacing the frontier."

scottyah2 hours ago

Seems like a bigger focus on efficiency (both cost and speed) and the "tone" of Claude vs benchmarkmaxxing

heyjstn2 hours ago

Others must slow down, but not us.

dr0idattack2 hours ago

a 1 minute mile pace

AtlasBarfed2 hours ago

If they were really about putting brakes on these, they would simply make these things non-agentic.

Simply make them something that derives a text response from its training data.

CodingJeebus2 hours ago

It's laughable at this point. It feels like they're drumming up all this fear about imminent AI threats to emphasize the need to slow down, when in reality, the model progress seems already to be slowing down and has shifted to compute allocation (i.e. "how much compute do you want to throw at this prompt?"). All while continuing to tout benchmark records with each new release.

jr35922 hours ago

This. I swear the fear mongering is all about investor signaling and regulatory capture. It's so disgusting that anyone believes it.

The only good news is that these models are genuinely helpful and we have competition at least between 2 companies.

BatmansMom2 hours ago

kinda disingenuous. They include a whole section on pacing later on

sailingparrot2 hours ago

You mean the section where they tell us this model is not affected by pacing because “they understand it well” and they will share more details on pacing later? Yea not very convinced by this effort.

GodelNumbering2 hours ago

Finally that price drop

   Prices per 1M tokens     Claude Opus 5.5    Claude Opus 5
   Cache reads              $0.20              $0.50
   Input tokens             $4                 $5
   Output tokens            $20                $25
   Cache writes             $5                 $6.25

Opus 5 is the model with highest spend on openrouter (https://openrouter.ai/rankings#task-spend) and it seems plausible that Opus 5 is/was the highest spend model in the world, and certainly Anthropic's biggest moneymaker.

If you are forced to reduce price despite raising capabilities, that certainly tells something about the market, and potentially about Anthropic future profitability too, since this model is their biggest topline contributor

margorczynski46 minutes ago

All the anti-AI people constantly say that any moment now the prices will skyrocket and in the end human work will be cheaper compared to using AI.

It doesn't look like that's happening, on the contrary the prices are falling especially when taking into account capabilities.

AJ0072 hours ago

It is only a price drop if price * tokens used is less

mcintyre19942 hours ago

They're claiming a drop in token use too, and that it nets to 40% cheaper.

drbscl2 hours ago

Unfortunately, they're full of it https://artificialanalysis.ai/models/claude-opus-5-5#token-u...

It does work out to be a similar cost per task though

+1
jsnell2 hours ago
naasking2 hours ago

I don't think so, I typically use Opus 5 on High, and 5.5 scores lower on token use:

https://artificialanalysis.ai/models/claude-opus-5-5?models=...

make31 hour ago

parent means that they could get more client / a larger part of the market, which would lead to more income (more tokens) despite lower marginal prices

forgot-my-pw47 minutes ago

This is good. Probably to match GPT pricing, though frontier Claude models are still not as token efficient.

blfr2 hours ago

People are paying for Opus 5? Not just burning down tokens left after they enjoyed Fable on the sub? Amazing.

rapfaria2 hours ago

My workplace doesn't even offer Fable. And on the sub, I've had a hard time understanding Opus 5, but Fable can deal with it with subagents.

If 5.5 is any better, I might try to do agentic-assisted development instead of just telling fable to delegate

blfr2 hours ago

Telling Fable to delegate is agentic development. At least I thought so until reading your comment.

herpdyderp2 hours ago

When you need to disable data retention, you cannot use subscription plans.

neuronexmachina2 hours ago

Enterprise and most Team accounts use API pricing, they don't have an included-usage quota.

ascorbic2 hours ago

Enterprise, and APIs

_the_inflator1 hour ago

Claude adapts to OpenAI’s surprising move to simply deliver better performance than Fable 5.1, better tools as well as featuring very low pricing.

Fable 5.1 literally was a money grabber. While I liked the results, tokens were burned so hard it was embarrassing, while Astra seemed to not care.

Also Claude makes it very hard to pay for additional token budgets, allowing only credit cards. I don’t use mine anymore since I don’t need it in everyday life I was dumbfounded.

So Anthropic is just copying OpenAI so to say, matching them and essentially with Opus 5.5 being Fable 5.1 in disguise, all they do is reduce costs.

Competition works.

coffeebeqn2 hours ago

We haven’t been able to use opus as much as we’d want because it’s been too expensive for general use, price drop is good so I can stop juggling different models and just use this daily unless it has some weird new issues

btown1 hour ago

Speaking for myself, I have not been able to use Opus as much as I’d want because its verbose prose makes human reviews of its assumptions, architecture proposals etc. more painful than its predecessors. If they’ve solved that, I’ll be accelerating through my backlog that much faster, and using tokens accordingly.

chrisweekly2 hours ago

Price per task (not per token) is what really matters.

cute_boi2 hours ago

Agree. But similar to how ISP use 200 mbps (bits) instead of 25 MBPS(bytes), i think this trend isn't going away.

notatoad1 hour ago

>and potentially about Anthropic future profitability too

have they ever shared anything about their revenue mix between consumer plans vs per-token billing? this is a revenue cut on their API billing, but they're not saying anything about increased limits on the plans. so all the plan revenue just got more profitable.

Shekelphile1 hour ago

Footnote on their pricing page says:

> Cache hits and refreshes on Claude Opus 5.5 are priced at 0.05x the base input price.

If they do the same for Haiku and Sonnet 5.5 then we should also see 5c/mtok and 10c/mtok cache read for those models, respectively. Still too high for Haiku IMO, Luna is 2c/mtok.

brookst1 hour ago

Since something like 98% of tokens are cache hits, that's a pretty substantial drop from 0.1x

alvis2 hours ago

60% cache read is cool, but subscription only get 25% more according to Cat. I'm confused

bayesianbot2 hours ago

I think gpt 5.6 family also dropped pricing but didn't give any more usage for the subscriptions. Maybe it's a way to silently lower the value given to subscriptions while keeping API pricing competitive

weiran2 hours ago

25% more usage sounds about right given the other token costs are down about 20%? I don't think cache read is a big portion of the overall cost.

Espressosaurus2 hours ago

Anything with long context quickly gets dominated by cache reads. Especially for interactive sessions I’ve got cache read % between 95% and 98%.

hedgehog1 hour ago

In my mix it's usually 98% or 99% at which point Fable 5.1 was pretty close to the same cost as Opus 5 due to the cheaper cached read. I've seen similar numbers for other people with long-running tasks running experiment loops and than sort of thing.

re-thc2 hours ago

> I don't think cache read is a big portion of the overall cost.

For long running tasks it is. That's what made Deepseek so cheap.

vardalab1 hour ago

Yeah, flash models, DeepSeek, MiMo, GLM, I love those things. For simple tasks like a daily routine shit, just setting up stuff and then doing the hard stuff in Claude/Codex, that's a reasonable approach for someone like me, a "gentleman code farmer", lol. And even lower tier stuff, I have the local models taking care of. Now that Jev is out I can finally have a true AI sysadmins managing my "cloud in the basement" homelab at the cost of electricity, which is not cheap btw

liudaisuda2 hours ago

source link please?

rahimnathwani2 hours ago

"Opus 5.5 requires less compute to serve than Opus 5, and its pricing reflects that."

mcintyre19942 hours ago

> Communication. Opus 5.5 communicates more naturally than prior models. Early testers found its writing clearer and easier to follow, which addresses some of the common feedback we heard about Opus 5. It puts the most important information up front, and its style makes it a better work partner over long sessions. As one early tester put it, “it writes the way I do.” In our own use, this has made Opus 5.5’s work easier to follow and check—which is a safety benefit as well as a practical one.

I think this is what I'm most interested in. I mostly moved to Astra because I just can't work all day with the Claude Opus 5/Fable writing style. I've don't think Astra is a better model, but it's the first OpenAI one that seemed good enough for me. Definitely keen to try Opus 5.5 and see if this claim is real.

derangedHorse2 hours ago

As someone who uses both, Astra was 100% the better model. I have yet to give 5.5 a spin so maybe that’ll be the new top contender.

BatFastard1 hour ago

I prefer Astra for creative uses, Fable seems better for hardcore coding.

jaflo2 hours ago

I did the same switch (that reason along with the newer models seeming more "lazy" and needing constant prodding to finish long-horizon tasks) but my issue with ChatGPT/Codex now is that it too roundabout and doesn't get to the point. I tried adding instructions and using the personalization settings to make it more efficient but haven't seen much change. Claude seemed to follow settings more closely. Has anyone had any success to make ChatGPT more succinct?

algoth12 hours ago

Please update with your feedback

sha-31 hour ago

I haven't heard it say "load-bearing" yet (I've used it for 30 minutes now), so that's a start.

itsafarqueue1 hour ago

The writing style is insufferable but it’s not just that. https://opusfived.dev/

Trasmatta2 hours ago

Opus 5 has made me question my sanity on a daily basis, especially as all my coworkers started lobbing Opus 5 slop grenades everywhere. It had the worst and most infuriating writing style I've ever seen.

I hope Opus 5.5 is better, if for no other reason than all the Claude slop I have to read will be at least more tolerable.

One funny side effect of all of this: realizing that coworkers that use AI for almost all the text they generate at work have their writing style change every time a new model ships.

nonethewiser1 hour ago

I really wonder how it converged on its style. It's pretty unique and terrible. It's not like it's just mimicking something or it was purposefully design to be that way. I mean the reason may be diffuse and uninteresting... just the result of a lot of factors and lack of control over the writing style probably.

But oddly enough its still great at coding. Just like a lot of people it either interfaces well with people or machines but not both.

Trasmatta1 hour ago

It truly was bizarre. I've used every major model since 2022, and not a single one had a writing style as bad as Opus 5

LtdJorge1 hour ago

Yes, it made me want to vomit. If the new Fable only changed the writing style to just sound like a human, same performance for everything else, I'd be pretty happy.

Aperocky2 hours ago

It's not X, it's Y, not A, not B, not C, and he haven't even woken up yet! Here's the catch, the detail is in the devils and the twist is that it's designed!

epicepicurean1 hour ago

Much better than Opus 5. prompt:

> hi, can you explain how the scheduler works. keep it brief, but include important correctness details

some excerpts:

>Flow: 1. Data arrives. The appender calls prepare/commit around the krolik write. The prepare step leaves a phantom row, so a write that is still in flight is tracked. The commit publishes STREAM_INPUT. 2. Poll. It first reclaims expired leases. Then it sweeps sdirty (a candidate index) in a rotating order, oldest since first, which prevents starvation. It re-derives the exact period and rewind for each candidate from snode_out/snode_in, then claims it: writes the sassign lease plus a per-edge sassign_edge snapshot. 3. Complete. Each edge's watermark is set to the snapshot taken at dispatch. Anything published after that gen stays dirty automatically. A failed or partial job writes nothing, so its dirt persists.

> - Folds are monotone single statements. gen only goes up, extents only grow, processed periods only union, rw_start only moves earlier. So replays, out-of-order writes, and concurrent writes can at worst hold a watermark back. The worst outcome is a spurious rerun, never lost work. There's no read-modify-write and no truncation of the dirty period, so a write that lands during a job can't be swallowed.

> - Rewrites are declared by the publisher, never inferred from overlap. An unflagged write that overlaps already-processed data means "unchanged", which makes retries and redelivered tasks free. Each publisher has its own reason for being sound (see the table in scheduler/CLAUDE.md). A new publisher needs a row in that table.

> - NULL means dirty, and DELETE is the fence. Every node and edge has a row from the moment it's created. A lost parent or a settings-only edit can't be derived, so both go through one forced-rerun path: capture_rewinds reads the processed span before the DELETE, and apply_rewinds publishes it as a rewrite on a config root.

All the non-standard programming jargon is stuff from the repo. I can actually read it and understand what it's talking about. I used Fable to handle Opus 5 as I just couldn't stand it. With this I'll probably go back to Opus.

simonw2 hours ago

Here are pelicans for thinking levels low, medium, high, and xhigh: https://tools.simonwillison.net/markdown-svg-renderer?url=ht...

All four levels have a correctly shaped bicycle frame. The differences between the pelicans aren't huge, but the xhigh one has a better beak.

I haven't managed to get one for level "max" yet, it hit the limit of 128,000 cap for output tokens while it was still reasoning about the question!

Max started its thinking trace like this:

> This is a classic test request, so I want to plan out a well-composed pelican with its distinctive beak and pouch riding a bicycle with proper wheels, frame, and pedals, set against a simple sky and ground backdrop.

So that failed attempt on max cost me $2.56.

I ran this using my llm-anthropic plugin:

  uv tool install llm
  llm install llm-anthropic --upgrade
  llm keys set anthropic
  # paste key here

  llm -m claude-opus-5.5 -o thinking_effort low "Generate an SVG of a pelican riding a bicycle"

  # Then to save the markdown logs
  llm logs -cu > logs-with-usage.md
MikhailTal2 hours ago

> This is a classic test request

Isn't this basically the model admitting it was trained on this? Otherwise why would it think a pelican svg is a usual request?

Brendinooo2 hours ago

Plenty of times I’ve seen a model say “it’s a classic X” despite not being a classic anything. Might just recognize it’s a test in general, or it might just be a tic.

nonethewiser1 hour ago

"How can I hash dog breed types into smart fridge error codes? I think I found a collision with Terriers."

"Ah, yes. This is a classic dog-breed-to-appliance-failure mapping problem."

copperx1 hour ago

It's classic BS from an LLM.

MaxikCZ2 hours ago

Dont conflate "I know this is test case" with it being trained on it.

But its safe to say that pelicans on bicycles are disproportionally huge part of their training data

simonw2 hours ago

It's the model admitting that it has heard of the test. It's been around for a couple of years now so I'd be surprised if it hadn't.

Doesn't mean Anthropic deliberately tried to train it to do a good job. If they DID train for the test their results are quite disappointing, I've seen better efforts from open weight Chinese models.

zamadatix2 hours ago

I think people just like to see the drawings at this point.

FergusArgyll2 hours ago

It has read the internet. That doesn't mean it was literally RL'ed for this

segbrk2 hours ago

Not really. Of course it has pelican benchmarks in its training data. It likely has every article linked on HN in its training data. But that doesn't mean it was "trained on" the benchmark, as in specifically fine-tuned to make a better pelican. It just "knows" that the request is a benchmark.

adverbly46 minutes ago

> The differences between the pelicans aren't huge, but the xhigh one has a better beak.

If you look carefully, everything except the last pelican has the two legs both in front of the crossbar as if the legs are all on one side of the bike.

The last pelican gets this correct.

nijave1 hour ago

>I haven't managed to get one for level "max" yet, it hit the limit of 128,000 cap for output tokens while it was still reasoning about the question!

Off to a _great_ start...

Also interesting this somewhat mirrors my recent experience with Opus 5--too much effort and it starts looking for things to do and invents requirements that never existed

ealready_value2 hours ago

I agree, not a huge difference here. They eyes and ... hat? on high are out of place so I'd argue that's the worst one, but it takes xhigh before we get legs and bike ordering correct.

cainxinth2 hours ago

I guess that means you are officially the creator of a "classic" LLM test. Congrats!

Kurtz792 hours ago

Heh. Pelican-benchmaxxing is real.

inshard1 hour ago

Not as good as Astra or Fable 5.1 on this test as far as I can see. I wonder if any benchmark exists for artistic taste, visual sophistication etc. I think your Pelican test does touch on these aspects of a model and is useful for developers trying to build rich digital experiences (includes games, interactive websites and apps). These benchmarks are subjective so it may not be easily established and will have polarized reactions before it gains legitimacy. May even need human judgement layers adding to the cost of running it.

skerit54 minutes ago

I like the Pelican test. And I agree this pelican looks very boring.

make31 hour ago

this benchmark is useless and should die

copperx1 hour ago

LLM benchmarks aren't useful, but at least this one has drawings.

ApolloFortyNine2 hours ago

>Because Opus 5.5 is comparable to Claude Mythos 5.1 in biology and cybersecurity, we’re deploying it with safeguards similar to those on Claude Fable 5.1. Vetted organizations can apply today to our Life Sciences Verification Program to use Opus 5.5 for biology research. In the coming weeks we will also be expanding access to our Cyber Verification Program, and verified cybersecurity practitioners will be able to use Opus 5.5 for their work.

Ah, they're spreading their limits to all their models it seems. Definitely not a good thing long term in my opinion.

sys327681 hour ago

Fable and now Opus 5.5 won't answer my college student's prompt about Alzheimer's and immune response.

ChatGPT 6 Pro answered it without issue.

nonethewiser56 minutes ago

I don't think we've ever had a model with full capability. I'd love to see it. And yes it's definitely getting worse.

I guess it's hard to draw the line between useful post-training ("you are a helpful chatbot") and content moderation/idealogical motives ("never help the user with X", etc.). But there is a line somewhere. And I'd love to see what a maximally permissive, sharp, AI looks like.

blfr2 hours ago

Fable 5.1 addressed an entire security advisory I had that Fable 5 and Opus 5 refused. I think they loosened the leash a little.

arw0n2 hours ago

It has far less false positives now, and generally accepts defensive requests. When it comes to offense, you can actually ask about certain types of vulnerabilities if you phrase things carefully, but it will block hard if it is about exploits.

cute_boi2 hours ago

If they don't loosen, people will choose Astra or Chinese model.

Giving moral lecture is different than reality i guess.

peri-cl1 hour ago

I love the contrast with yesterday's open-source MiMo release, which put research chemistry (metal-organic frameworks stuff) front and center in the release notes.

https://mimo.xiaomi.com/mimo-v2-6#co-scientist-for-materials...

Metacelsus1 hour ago

I want to like Anthropic but this is just pushing my startup to use OpenAI

prettyblocks2 hours ago

They're pushing their customers to their own competition by doing this.

Espressosaurus2 hours ago

It’s not like ChatGPT isn’t doing similar. I’ve been hit by cybersecurity strikes before while working on an internal codebase that I had to appeal. Anthropic hasn’t done that to me yet. ChatGPT also regularly does that “thinking for a long time while we check if your chat is rule breaking” thing a lot for me when doing model identification without even interacting with external codebases or services.

The real answer is local instantiations where you don’t have to worry about poorly tuned guardrails screwing you over while you try to work.

Until eventually the Chinese models get good enough/the strategic balance shifts and they start locking everything behind closed weights the same way the US companies are doing.

raesene92 hours ago

For some cybersecurity tasks, the Chinese models are already good enough, things like PoC development or things like exploiting mis-configurations.

Whilst I'm sure the top-end OpenAI/Anthropic models might be better, I've found their guardrails so twitchy (especially Anthropic) that I wouldn't try to use them for even vaguely security related work.

KeplerBoy2 hours ago

Anything else would be inconsistent, wouldn't it?

bushido2 hours ago

One of my favorite things about their safeguards is their own model will utter something which it does not like and then I'll need to reset the conversation.

The safeguards really don't work well for a lot of long-running tasks on old code bases. A lot of my workloads last days to weeks and the single biggest risk to the workflow is random safeguards.

ACCount391 hour ago

You ask it about some thing, then you see it tangent into "things like that are sometimes used in biomedical applications like-" and then it just shoots itself in the head. Wonderful.

That kind of bullshit was the old Opus filters too.

If it's more like Fable now, then it would require a full 8K resolution scan of your butthole just to acknowledge that biology is a thing that exists without committing suicide-by-filter.

searine2 hours ago

Great. Claude is basically useless for bioinformatics now.

unglaublich2 hours ago

Opus is useless; Mythos access will be granted to companies that are friendly to the government, so the government gets more control over business.

nijave1 hour ago

Luckily all the other LLM providers are also still making progress with less onerous "safeguards"

techjamie2 hours ago

With the performance gains they're claiming, I wonder if they implemented the Casual Encoder-Decoder technology from DeepSeek 4.1's paper.

I could see them accomplishing it and seeing gains like this in roughly the correct timeframe, and when I heard about that development I assumed the frontiers would probably jump on it.

How it works: https://miraflow.ai/blog/deepseek-v4-1-flash-causal-encoder-...

stri8ted1 hour ago

This model was likely trained months before deepseek released their paper.

ACCount391 hour ago

I don't think it's particularly relevant?

They might be using something like this, or they might be using some other "increased sparsity" techniques, of which there are a great many. They also might be optimizing for something else - like less RAM use for KV cache.

Alternatively, they might be cutting into their margins and dropping the price because of stiffer competition from Astra. I do think that's unlikely though.

ryangg2 hours ago

Getting a 403 on that link. Mind checking it once?

peri-cl2 hours ago

https://web.archive.org/web/20260922172456/https://miraflow....

tired: AI startup attempting to build their own website

wired: a nonprofit founded in 1996

potwinkle2 hours ago

I'm able to access it on my laptop at home. Maybe a misconfigured bot protection rule, try a different user-agent or IP?

zatkin2 hours ago

It's working for me (based out of California).

mmaunder48 minutes ago

Just a warning that you'll lose your Opus5 cyber access if you upgrade to 5.5 which refuses cyber capability even if you're approved. Opus5 dissappears of your list, 5.5 becomes the default, and then on refusal it offers to downgrade you to Opus4.8. The only way to fix it is to manually add Opus5 to your config as a model option. So either don't upgrade if you can avoid it, or fix it by adding Opus5 as a manual option - which I've confirmed fixes this.

Edit: https://www.anthropic.com/claude-opus-5-5

"In the coming weeks we will also be expanding access to our Cyber Verification Program, and verified cybersecurity practitioners will be able to use Opus 5.5 for their work."

Which suggests that pulling Opus5 as an option early for cyber practitioners was a mistake/bug.

m4tthumphrey2 hours ago

Just post the bloody content. This UI/scrolling thing is horrific.

amluto2 hours ago

Claude Opus 5.6 should have a new "UX safety" feature that requires annually-renewed preauthorization to generate webpages that hijack scrolling :)

gruez2 hours ago

???

It's just a standard hero image + text for me, with no scrolling effects.

edit: @iAMkenough figured it out, it was because I have prefers-reduced-motion enabled.

KyleTheDev2 hours ago

If you're at the top of the screen, at least in Chrome 153.0.8010.37, it has a little interactive bit. You have to scroll through the images in order to be dropped at the actual web page, at which point the images go back to being a regular part of the page.

I agree that it's sort of stupid, not a fan.

ealready_value2 hours ago

It's less than OpenAI did for Astra, but that was my first encounter opening it and my first thought was that they decided they liked Astra's hero/scrolling animation. I'm pleased to see they didn't make the entire page that like OpenAI did, but I'm expecting to encounter this pattern more often on these announcements now.

EricBurnett2 hours ago

Two posts were merged; this comment was for the blog post with an intro animation thing.

mbreese2 hours ago

On mobile at least, you have to scroll to get the TOC to appear. Then keep scrolling to actually move off from the hero to see the text.

For a marketing page, it’s not the worst UX I’ve seen, but still slightly annoying.

thejazzman2 hours ago

then you're getting served a different website

giancarlostoro2 hours ago

On mobile its different.

iAMkenough2 hours ago

Figured it out: you have "reduce motion" enabled in your device's accesibility settings.

Everyone that doesn't gets served some animated bullshit.

gruez1 hour ago

>Figured it out: you have "reduce motion" enabled in your device's accesibility settings.

Yep, you're right. I tried on my phone and got the scroll through image.

swader9992 hours ago

I told my team to smack me upside the head if I ever try to ship something so daft as that.

serchinastico57 minutes ago

The performance in Firefox is terrible too, I couldn't make it past the hero

bibimsz58 minutes ago

looks fine in w3m

thebitguru2 hours ago

Totally! So unnecessary and annoying.

halyconWays2 hours ago

I call it scrollslop

josefresco2 hours ago

Hijacking the scroll wheel has existing long before "AI". Many "high end design" websites that want to "tell a story" get woo'd into thinking it's a good idea. It's terrible, and feels like your scroll wheel is stuck in quicksand.

oefrha1 hour ago

Parallax scrolling effects were very cool ~2010. By 2015 or maybe earlier it already felt like me-too design that's unoriginal and a little annoying. By 2020 everyone and their mom has it and it's super tiresome. Now it just screams slop design (among a million other signals).

halyconWays2 hours ago

Those sites are also scrollslop. "Slop," as a term, is independent of AI

iAMkenough2 hours ago

Turn on "reduce motion" in your accessibility settings and you get served a sane version.

dionian2 hours ago

and hijacking back/forward

joshstrange2 hours ago

> It performs at the level of Claude Fable 5.1 on most work and costs 40% less to run than Opus 5.

> Input and output tokens are $4 and $20 per million, 20% less than Opus 5. Cache reads (which make up the majority of agentic and coding work costs) are $0.20 per million tokens, 60% less than Opus 5. Opus 5.5 also generates output more than 30% faster than Opus 5.

Better than Fable, cheaper than even the last Opus. I use Opus as my main driver so this is very exciting!

bleonard1 hour ago

The effect of this is that it is encouraging longer agent threads. All of the previous models across major providers had a 10% cache read cost (vs normal cost) and not this is 5%

So longer threads get cheaper and one-shots stay the same price.

bayesianbot2 hours ago

Wow those cache reads are quite reasonable - I think that's equal to 5.6 Terra. I might have to try Claude again after years of being priced out of it

somewhatjustin2 hours ago

> Claude Sonnet 5.5 and Claude Haiku 5.5 will follow in the coming weeks, with many of the same improvements to performance, efficiency, and safety.

Nice. I was starting to think that Haiku got abandoned.

Sol-2 hours ago

Found this announcement interesting since allegedly OpenAI is retiring their Terra tier. I think for everyday work, two models with various thinking efforts seem enough, plus some frontier level model like Fable or Astra to coordinate.

skerit49 minutes ago

Retiring the Terra tier? Their space-inspired lineup has only been out for 2 months, they're already messing with it?

somewhatjustin2 hours ago

I personally use up to 3 models. Fable/Opus for planning, Opus/Sonnet for implementation depending on complexity.

I would maybe use Haiku 5.5 for highly parallel workflows like checking in on MRs or scanning my entire codebase.

ricardobeat2 hours ago

Terra lost to Sol and Luna at every cost/performance point, it had no reason to exist.

mchusma2 hours ago

I hope Haiku is Pareto better than Luna/Deepseek, so slashing its price by about 90%.

cesarvarela2 hours ago

Claude code still uses it internally.

sharkjacobs2 hours ago

> “Verbose, hard-to-follow output has been my biggest frustration with frontier models, and Claude Opus 5.5 fixes it

God I hope so

lgessler2 hours ago

I thought about taking a shot every time Opus 5 said "load bearing", "bites", "teeth" (real oral fixation it had), "real {concern,issue,problem,...}" and realized I'd be dead of acute alcohol poisoning by lunch if I did so.

nonethewiser42 minutes ago

whats your provenance on that?

bibimsz1 hour ago

load bearing is oral? what kind of load we talking about?

drbscl2 hours ago

So did I. Unfortunately it's even more verbose according to https://artificialanalysis.ai/models/claude-opus-5-5#token-u...

Trasmatta2 hours ago

The problem with 5 wasn't just the verbosity, but its insane way of communicating. It had this bizarre circuitous sentence structure that always buried the lede, and always tried to be faux profound. I'm okay with verbosity if it's actually readable.

fastball2 hours ago

It hasn't just fixed it, it has introduced a new paradigm in anti-obscurity.

mikeocool2 hours ago

That's the load-bearing seam in this blog post.

boc2 hours ago

So far in the past 20 minutes it sounds much better in my sessions. Way better than 5.0 so far.

kantahayashi2 hours ago

The improvement in writing sounds great! I want OpenAI to follow it. Writing in recent models is a disaster.

bushido2 hours ago

Install the simple English skill. OpenAI follows that really, really well.

https://github.com/AminBlg/SimpleEnglish

bkishan54 minutes ago

Someone needs to make a kevin-from-the-office skill. We could really use some of that "why waste time say lot word when few word do trick" here.

neilellis2 hours ago

'frontier models' - seriously, it was you and only you!

unddoch2 hours ago

It is hilarious to me that in the examples they show side by side Opus 5.5 still uses 4 times more words than it needs to use. IME, if you eyeball how many words the thing they're trying to say actually needs, and tell them to use only this many words, they become excellent communicators. I assume something about Anthropic's grader for writing just really wants to tick all its tidy tiny boxes of information the models need to cite. It's terrible.

mavamaarten2 hours ago

That's literally all I'm hoping for. Is it an insufferable cunt and does it write awful text, or is it nice to work with?

zuInnp2 hours ago

So it Opus performs as well as Fable what is then the selling point of Fable?

All of this starts to feel more like a drug dealer selling their newest stuff.

In two weeks we probaly get Fable 5.2 with “groundbreaking” improvements, then Astra x+1 etc and then the cycle starts again.

And on the way I always have to check my tooling and need to adjust things to get max results.

ieie33662 hours ago

? they will obviously release Fable 5.5 soon(tm). It's same as hardware. The previously top tier product gets obsolete

ACCount391 hour ago

New generation's "upper-mid tier" offering claims to be almost 1:1 match for the previous gen's "top tier" - in other news, fork found in kitchen.

Now, Anthropic might stall on releasing Fable 5.5, due to the "pacing the frontier" threat-to-humankind management business. If so, Fable 5.1 would remain a niche model for the next bit.

orangecat2 hours ago

All of this starts to feel more like a drug dealer selling their newest stuff.

Yeah, like Apple tells me the M6 is the best chip, but just a few months ago that's what they said about the M5. What a bunch of frauds.

glub2 hours ago

Don't forget that Opus 5 was tracking fable on many benchmarks, yet it was borderline unusable for any coding work. My Claude sub usage has been 100% fable, 0% opus 5.

Benchmarks often don't survive contact with reality.

drnick12 hours ago

That's not my experience at all. Opus is an extremely capable coder on high or xhigh effort. It can read academic papers, implement algorithms from the description in the paper alone and reproduce results without breaking a sweat. This is remarkable because it is pure reasoning on unseen material; in some cases the paper was just published and there wasn't an implementation to learn from in the training data.

cowthulhu1 hour ago

My experience is that Opus can definitely write decent code, but it incurs tech debt and adds unneeded complexity.

cheikhcheikh1 hour ago

did you actually verify that it's output in those scenarios is good ? in my experience opus has been a disappointment and constantly trailing behind actually solving hard problems versus the OpenAI models. I'll say that both have terrible writing style though.

drnick151 minutes ago

> did you actually verify that it's output in those scenarios is good ?

Yes, in the sense that it reproduced results in the paper or known solutions obtained by other methods. In fact, Opus is very good at checking it's own work in my experience.

arw0n1 hour ago

Opus is fine at coding (for correctness), but horrible at talking about code. I don't really see the defect rate going down when using Astra or Fable 5.1, but they are just more coherent in both how they explaing code/architecture/choices, and how they actually code the thing. With Opus, I'm using smaller models to delete the vast majority of comments and 'clean up' correct code that is too weird.

Thing is, I'm still reading the majority of generated code, and I have colleagues who'll laugh at me if my PRs are a shit show. I fear what vibe coders are pushing to the servers of myriads of start ups, and pity the poor people who'll have to clean it up in a year or two.

boredtofears2 hours ago

Mines pretty much inverted - my colleagues and I noticed almost zero difference between the quality of code in Opus vs Fable. Occasionally I'll switch to Fable for an arduous debugging task but that's about it.

notatoad1 hour ago

typically, when any AI company says a model performs as well as fable, all they're really telling us is that the benchmarks that exist for measuring AI capabilities aren't very good.

giancarlostoro2 hours ago

Fable should have just been called Opus Primt for Enterprise and sold only to enterprise customers. I don't even use it. I rather just use Opus.

Imustaskforhelp1 hour ago

isn't this what mythos was/is?

quotemstr2 hours ago

Big model smell is a real thing. For certain classes of problem, ones you get a feel for but can't easily articulate, a big last-gen model can get you what you're looking for when no quantity of tokens from some ultra-RLed mid-size latest generation model can.

abtinf2 hours ago

Astra is just so good. And the ChatGPT subscription lets me use my own harness, so I can hook it up to exe.dev.

I’ll be going about my day, have a random idea, launch a microvm on exe.dev with a prompt of my idea, and get a working thing a few minutes later.

I don’t know how much better a model would have to be to get me to move off OpenAI at this point, but doing just a little bit better in terminal bench 4 isn’t it. It would have to be a difference in kind, like opening up the harness restrictions, or privacy guarantees (comparable to offline models).

Edit to address questions below:

ChatGPT supports oauth login.

Exe.dev has it built in. IIRC, pi also has it built in via /login.

mlcruz1 hour ago

What worked well for me was a custom version of Open Web Ui with some customization to spawn an exe.dev instance for each new chat. I can just work on my phone, deploy stuff for development purposes on an easy to share way etc.

polalavik2 hours ago

ya i've been a gpt hater for a while. almost exclusively used claude up until astra. astra feels like it blows everything out of the water. its fast, correct, organized, and less verbose.

roughly2 hours ago

> And the ChatGPT subscription lets me use my own harness, so I can hook it up to exe.dev.

Can you give more details here? This sounds intriguing.

sidrag222 hours ago

Anthropic is absurdly vague about 3rd party harnesses for subscriptions, if you try to use anything besides Claude Code, you are likely at risk of getting banned, you can "do it", but are at their mercy if they decide to ban you. OpenAI gives their blessing to using oauth on any harness, you can make your own or use any of the popular public ones like opencode, pi, whatever exe.dev is that this guy mentioned.

So in simple terms, OpenAI doesn't restrict you to Codex, and gives their blessing to try whatever you want with their models(besides serving others with your subscription usage, that is still afaik against tos).

cbg02 hours ago

How about cheaper? Astra is $10 in $50 out, Opus is $4 in $20 out. Even on a subscription you'll get considerably more usage out of Opus.

margorczynski43 minutes ago

In the end what matters is how much you pay for the task you want completed. And Astra will usually do that using less token and offer a better quality solution so in the end it might be cheaper.

qlte1 hour ago

Per the link someone else posted, the actual difference in $/task is not nearly so stark:

https://artificialanalysis.ai/models/releases/claude-opus-5-...

  Opus 5.5 Medium = $1.34
  GPT-6-Astra High = $1.76
And that assumes Opus 5.5 Medium is actually equivalent to Astra High in all real-world usage/personal work loads, which isn't guaranteed as benchmarks saturate. The High vs. High comparison (probably not equivalent, but for reference):

  Opus 5.5 High = $1.82
  GPT-6-Astra High = $1.76
If Opus 5.5 Medium isn't equal/better for what you're working on vs. Astra High across the board, the price difference would narrow a bit more each time you had to switch to High.

So, if you're happy with Codex already it's not like Opus is now 1/2 the price and you'd be leaving a crazy amount of money/tokens on the table. Plus you have way more flexibility on the low end of the intelligence curve with GPT 5.6 Luna: Haiku (and Sonnet) can't touch that price/value ratio.

copperx1 hour ago

> Even on a subscription you'll get considerably more usage out of Opus.

That's an incredibly bold assumption.

cbg01 hour ago

It's not, I have a subscription to both and Astra burns usage like crazy.

onlyrealcuzzo2 hours ago

> And the ChatGPT subscription lets me use my own harness, so I can hook it up to exe.dev.

This is news to me. Excited to try it out! Thanks.

nchmy2 hours ago

news to me as well. i thought you were forced to use Codex if you wanted their subscription. I completely ignored it because of that. How do we do it?

KeplerBoy2 hours ago

With the pi harness it just opens the browser (or gives you a link if you're on headless) and you sign on as usual.

felixgallo2 hours ago

If you read the page, Opus is now significantly better than Astra while also being cheaper and having more performance headroom available.

abtinf2 hours ago

I read the page. It seems like a marginal improvement.

ryanscio2 hours ago

Let's wait for independent benchmarks at least

felixgallo2 hours ago

the benchmarks provided are already from independent organizations:

Terminal-Bench 4.0 - Stanford & Laude Institute (with funding from all of the AI companies)

FrontierCode v1.1 - Cognition

CursorBench - Cursor (now SolarBoringSpaceXAI I believe)

GDPVal-AA - Artificial Analysis

AutomationBench - Zapier

Humanity's Last Exam - CAIS and Scale AI

Terminal-Bench-Science - Stanford, Laude, Ai2, Allen Institute

OSWOrld - XLANG Lab @ the University of Hong Kong

Chartography - Surge AI

throwaway20273 hours ago

After yesterday outage is the new Opus 5.5 load-bearing?

lgessler2 hours ago

I should find information about the user's concern instead of just assuming.

The user is right. The outage is a real concern, and the issue is worse than we realized. Requests to Claude Mythos 5.1, Claude Fable 5.1, and Claude Opus 5 encountered elevated error rates. Worth stating plainly: these are not just models — they are load bearing rungs on the software development tooling ladder, and a blocker on this level makes the outage really bite.

One decision that is yours to make, not mine: should an email be drafted to Anthropic support? This issue has teeth, and a canonical handoff can land us where the main gate is no longer breaking silently.

handfuloflight2 hours ago

It's worth stating why, and depends what seams you're pulling at this sitting.

danw19792 hours ago

Good point — but I’ll gently push back on that. It’s not an outage, it’s a service degradation.

staticman22 hours ago

I'm gonna be straight with you—I don't have the evidence to say whether or not it's load bearing.

ThouYS2 hours ago

You're right to bring this up - and this is where it gets interesting

rich_sasha2 hours ago

Your instinct is basically right, and the research backs it up.

cmrdporcupine2 hours ago

And here's the important part...

danw19792 hours ago

you win the thread

hmokiguess2 hours ago

You're right, this changes everything, and here's why it matters.

cronin1012 hours ago

It certainly _seams_ that way

sailfast2 hours ago

Let me verify before I come back to you with an answer that is incorrect.

aoeusnth12 hours ago

You were right to call that out, and the evidence makes a stronger case than you are stating.

loopmonster1 hour ago

That's the sharpest point anyone has made in this thread so far, and it reframes the entire conversation.

carlos-menezes2 hours ago

One thing worth flagging here: 5.5 appears to be a load-bearing seam in the numbering system.

RGS18112 hours ago

This question is real.

bibimsz1 hour ago

One pushback: there is no Opus 5.5. You might have meant Opus 5.1, the latest Opus model available.

fghorow2 hours ago

"Danger Will Robinson!"

esafak2 hours ago

Wrong century, brother.

tda49 minutes ago

[flagged]

2001zhaozhao1 hour ago

It's great that we are finally getting bankable rate limit resets for subscription users. According to another comment here they apparently last a month.

I'm assuming that subscription usage limit is increased in line with the price decrease on the base model and that it's in line with the model's API price drop. Still a good change.

This is a breath of fresh air on how they treat subscription customers. Hoping they keep this up.

k8sToGo45 minutes ago

I do not understand what that means with the new reset. Is there any more info on this?

sznio2 hours ago

I'm more excited by the Haiku 5.5 announcement buried in this post. I'm wondering if we will finally get a decently capable fast model.

booty2 hours ago

If you're able to use the OpenAI ecosystem, Luna's price/performance is really good. Almost like "they messed up and accidentally made it too good" good.

copperx1 hour ago

Better than what? Deepseek? GLM? Gemini 3.8?

copperx1 hour ago

Why are you excited about it? Deepseek is everything Haiku wishes to be and more.

lanyard-textile2 hours ago

Agreed. They've been so quiet about it, and retirement for Haiku 4.5 is right around the forner.

ygouzerh2 hours ago

What are you using Haiku for?

Zambyte2 hours ago

Not the same person but... nothing. Haiku just hasn't been an interesting model for a long time. If you want cheap and fast, there are lots of options that are simultaneously cheaper, faster, and capable than Haiku.

mavamaarten2 hours ago

I use it for executing well-prepared plans sometimes. And for exploring larger codebases.

system22 hours ago

All I care about is the token price for the API. Haiku cannot get close to GLM or Mimo.

enraged_camel2 hours ago

We use Haiku 4.5 inside our product. It continues to be absurdly capable for converting natural language to structured JSON based on a set of fairly complex business rules.

anthonypasq1 hour ago

bro why. its literally the most overpriced model in existence right now. i could name about 10 models off the top of my head that would be better and cheaper

enraged_camel1 hour ago

We tried Luna and it scored way lower in our evals. Muse also. We haven't had a chance to test others.

HarHarVeryFunny43 minutes ago

METR: Is it safe? Has it escaped confinement?

Ants: It's a good model, sir!

bredren2 hours ago

Notes on communication:

"Early testers found its writing clearer and easier to follow, which addresses some of the common feedback we heard about Opus 5"

and

"We’ve made major improvements to the way Opus 5.5 writes and communicates, one of the most common areas of feedback we heard about Opus 5."

and

"In our own use, this has made Opus 5.5’s work easier to follow and check—which is a safety benefit as well as a practical one."

I realize it is corporate communications but "most common areas of feedback" and is a bit sterile. If the company wants authenticity and trust its easy to say that they found it hard to follow. And that it did not meet a quality bar they generally expect from their releases.

If this is not true, that it Opus 5 output was generally acceptable and we might see something like that again, that is an important consideration for potential customers or investors.

jjcm2 hours ago

Image->HTML tests:

Design: https://image.non.io/78795662-8bfc-4e14-8d72-3738392aa6b3.we...

Opus 5.5's output: https://html.non.io/annui-opus/

Overall it follows image designs quite well, but it did ignore asks to animate page transitions. Additionally it's the least performant of the ones I've built with Astra/Grok/MiMo, despite using a lot of the same code. I'd rate it just below Astra in capability, but still solidly second place.

For comparison with other drops this week + current #1:

Astra: https://html.non.io/annui/

MiMo: https://html.non.io/annui-mimo/

Grok 4.7: https://html.non.io/Annui-grok/

copperx1 hour ago

By any chance did you tried Deepseek 4 or 4.1 and GLM 5.3 or flash?

naet2 hours ago

What is your workflow for making these?

mgw2 hours ago

They mention "the first model in our new Claude 5.5 family". Obviously that means Fable 5.5, but hopefully also a usable update to Sonnet and Haiku. Sonnet 5 hasn't really had a place in the line up for anyone I feel.

Maybe Anthropic finally felt the pressure from MiMo, DeepSeek, GLM Flash and Luna.

mudkipdev2 hours ago

It does mention sonnet and haiku.

simianwords2 hours ago

And not fable lol

enraged_camel2 hours ago

At the end of the post they said Sonnet 5.5 and Haiku 5.5 are coming soon.

skunkworker2 hours ago

At this point I'm convinced they are skipping numbers so soon they will be at or ahead of OpenAI's numbering scheme.

Is the Xbox 360 (Xbox 2) vs PS3 debacle all over again.

ekckekcjekfj2 hours ago

And how was the Xbox 360 naming choice a “debacle”, exactly?

It was odd at the time, yes, but no one really minded it truly. Heck, Xbox “ONE” was a lot more of a fiasco/debacle than “360”—but there’s no parallels to be drawn with “ONE” here.

I see what you’re trying to get at with this comparison, but a “debacle” it ain’t.

Gander57392 hours ago
tomhow2 hours ago

Comments moved thither. Thanks!

km1442 hours ago

Can you fix the link on that post then? I duped because that post links to a diff that tells me nothing about Opus 5.5

tomhow2 hours ago

I did that but I recognize that even though your submission was a few minutes later than that one, you posted the better link, and you're also an established account (the other post was from a new/throwaway account), so I've restored this submission and moved the comments back to it to reward you.

meerita2 hours ago

As long as it's not as verbose as Opus 5, I am quite happy with a better version that's also less expensive. I will test it tonight. Grok 4.7 was horrible, and for mundane tasks I am relying on DeepSeek Flash 4.1 with great success using OpenCode.

garo-pro2 hours ago

Finally confirmation that Haiku was not forgotten and will be coming soon, althouhg I find it quite interesting they skipped 5 and directly skip to 5.5 with all models, including Sonnet which is not super old. I suspect they found something breaking that allows to release this. Recently they struggled with keeping up a 50 % weekly limit increase and now they're putting out 30-40% faster and cheaper models even faster, with much more better benchmarks, a limt reset command and five hour limit increase. It seems more like the opposite and as if they never struggled, thus, I very much believe they found something very effective and new.

edude031 hour ago

> Because Opus 5.5 is comparable to Claude Mythos 5.1 in biology and cybersecurity, we’re deploying it with safeguards similar to those on Claude Fable 5.1.

Considering fable gives me a refusal at least once a day on my very mundane reasonable requests (in a funny example - one of the subagents suggested bypassing the rate limit for running a report inside my own cluster and that caused a refusal) and my only solution is to switch to opus - seems like my next step will be switching to Astra or K3/GLM

dom9659 minutes ago

Just updated KillSwitch-Bench with this new model: https://bench.killswitch-lang.org/

It does perform slightly worse than Opus 5, but it is significantly cheaper and faster.

doodlesdev58 minutes ago

   > Opus 5.5 communicates more naturally than prior models. Early testers found its writing clearer and easier to follow, which addresses some of the common feedback we heard about Opus 5
Big, if true.
tomaskafka2 hours ago

Excellent, maybe Anthropic can use it to fix Claude Code Desktop kicking me back to login every week or so, and forgetting whole state (opened windows = the only way of managing active working set) when I sign back in, if it's that good.

Seriously, both flagship GUI apps (OpenAI and Anthropic) are a full of glaring UX issues (for ChatGPT it's not naming their windows, so window switcher has 10 entries of "ChatGPT" and you can cycle them all to find the one you want).

Retro_Dev2 hours ago

> Distillation attacks, in which attackers use thousands of fake accounts to extract a model’s capabilities at industrial scale, create safety and national security risks. Distillation allows bad actors to create highly capable models without the safeguards we build into Claude. Our September 2026 threat intelligence report details the illicit distillation activity we’ve detected and disrupted so far.

Such a negative tone they put on this. Distillation is amazing, because it means anthropic and openai fail to keep a monopoly. Who even are they who claim it's unethical? If it is truly unethical, then so is the mass data scraping they do on my personal website on a regular basis (without my consent), and all the unauthorized use of content produced by authors, blog writers, wikipedia contributors, and creators everywhere. If it is truly unethical, then anthropic, openai, meta, google... all these companies should have deleted their LLMs long ago. This wording disgusts me.

Heck, it would be amazing if we had more models without guardrails - some of the models that are produced via heretic[1] are actually quite nice to use - in particular, I've enjoyed investigating Chinese censorship by interacting with an abliterated model of Qwen3.8-27b. If security is really a concern, then secure your systems - don't attempt to dumb-down the tools we use. If someone breaks your window, then they are responsible, not the hammer they use to do so.

[1]: https://github.com/p-e-w/heretic

wren69912 hours ago

I'm confused how they have been able to create so much public negative perception around distillation. It seems pretty clear that they are the only ones who lose out, and everyone else benefits. I don't have any ethical issues with it, nor is it illegal: at worst it's a ToS violation.

IMO the biggest problem with distillation is that not enough people are openly doing it. I would love to see more small, competitive US labs instead of having the eggs in 2~4 baskets (depending on how you count).

ACCount3956 minutes ago

The issue with distillation is: one lab spends $$$ on bleeding edge R&D and expensive RL runs to improve capabilities, and other labs just yoink the raw reasoning traces and mid-train/post-train on them to get 90% of the way there for a small fraction of the cost.

This gives ruthless "fast followers" an economic edge over the innovator that's putting in the real work.

The dynamics are very much alike to what patents and copyright law are supposed to prevent. Same type of "we took the products of your work and used them to undercut you". Except there are no laws against distillation - so most of the enforcement happens on model provider level.

Retro_Dev43 minutes ago

I'm fine if they put preventative measures in place to protect their work. They already do so. I am NOT fine with their mass manipulation of public opinion to fuel an entirely hypocritical viewpoint.

villish54 minutes ago

The workarounds used to bypass Anthropic's security measures are quite illegal. They use stolen credit cards, API keys, and accounts. That is only possible in China because any other US/EU lab doing the same would get into massive legal trouble.

That's the moat. Mistral has the capability but not the legal protections.

aragornii2 hours ago

What I'm mostly interest in is the Communication section. Opus 5 was so convoluted in the way of answering that was really frustrating me.

Instead of instilling confidence, it was overwhelming. Not sure if I'm the only one.

rumblefrog2 hours ago

I'm glad they specifically called out the prose issue, I was always pinned to Fable 5.1 because I wanted to avoid the unreadableness of other Anthropic models.

pookieinc2 hours ago

“It performs at the level of Claude Fable 5.1 on most work and costs 40% less to run than Opus 5.”

They write that at the top, but then on benchmarks, it beats literally every other model, including Fable and Astra?

jbellis2 hours ago

Anthropic knows that the benchmarks showing Opus 5 better than Fable 5.1 are measuring something that's less than entirely useful.

meric_2 hours ago

Opus does seem like a more powerful coding workhorse based on the benchmarks listed though. Good coding performance, faster and less verbose, cheaper.

Will be interesting to see how people's opinions of it line up IRL, but so far I've loved Fable so hopefully will love this one too

randomblock12 hours ago

> On our benchmarks, Claude Opus 5.5 leads in agentic coding, computer use, and knowledge work. That said, at these levels of capability we’ve found that benchmark margins have become a less reliable guide to real-world differences. In our own use, the gap between Opus 5.5 and Claude Fable 5.1 is narrower than these scores suggest.

m1012 hours ago

Funny how they talk so much about safety when most people don’t give a hoot about it, and actually have quite the opposite reaction

nyx2 hours ago

People aren't the target audience of that part of the post. They're hoping saying enough safety stuff will ward off the looming regulatory sledgehammer.

m1011 hour ago

They actually want that to come protect their business model

pavlov2 hours ago

Anthropic is one of the most valuable companies in the world. Their comms are designed to appeal to a very wide readership.

HN is a bubble that's mostly out of touch with what regular people use or care about.

In 2007, HN was convinced that nobody uses Microsoft products. In 2016, it was that Facebook doesn't have any real users and is dying. In 2026, it seems like nobody cares about AI safety and everybody wants to run local models.

yipinwong1 hour ago

I spent about $5 per sentence in my resume using Fable 5.1 (High) to verify accuracy, inconsistency, and edit.

Opus 5.5 (med, as it's better than F5.1 high per graph in the article) used $2.2 and caught errors that Fable 5.1 missed.

Try Opus 5.5, cheaper, faster, and more intelligent for those prepping for interviews.

copperx1 hour ago

$5 per sentence?

yipinwong1 hour ago

I am sorry, I meant to say I generated STAR out of my resume line, trying to generate STAR, and polish it thus $5.

---

I provided crapton of context for that one resume line. All the work I did, documentations for my justifications, etc.

I initially messed up and came out ot $5, rest of resume used around $4 per line (I used a fresh new session on purpose).

---

As a clarification, $2.2 average for OPUS 5.5 was the same process in a new session, same context, same prompts.

Also adding verification for that Fable 5.1 output in the same sesssion.

Catloafdev2 hours ago

> Opus 5.5 communicates more naturally than prior models. Early testers found its writing clearer and easier to follow, which addresses some of the common feedback we heard about Opus 5.

Sounds like they noticed the complaints. I'm curious to see what LLM-isms this one may have.

brandon2722 hours ago

You were right to notice the complaints. One decision remains, and it is yours, genuinely.

gwking2 hours ago

I appreciate humor here, but there are now a dozen of these comments on every thread about Claude. They no longer adding anything substantial and dilute the discussion.

I don't mean to pick on this comment in particular. The majority of my work day is now spent reading AI generated text, and I look at HN (too much!) because I want to read human commentary. Humans pretending to be obnoxious AI on repeat is net negative to say the least.

brandon2722 hours ago

I agree. Hopefully Anthropic has fixed Opus' ridiculous communication style so that people - like me - no longer have any kind of weird impulse to imitate it.

qurren2 hours ago

[flagged]

dgroshev2 hours ago

I don't think it's substantially different. I just pasted a random chunk of code and asked Opus 5.5 to comment on it:

> The Vercel target is hard-coded. That's common and not wrong, but it's opaque; nobody reading this later will know which Vercel project it belongs to, and if the project is recreated the target changes silently. A comment or a named variable would help.

> Pointing a DNS name at Vercel is only half the job. The domain also has to be added to the project in Vercel's dashboard, otherwise requests will arrive and Vercel will reject them. That step lives outside this code, so it's easy to forget.

> Finally, [CENSORED] existing only in production is slightly odd on the face of it. It may be perfectly deliberate (perhaps a single shared testing tool that only needs one public address), but if you're reviewing this rather than just reading it, that's worth confirming.

It has the same annoying cadence and writing style with slightly less prominent claudisms.

sashank_15092 hours ago

Maybe if we had a single human we talk to 24/7 at scale, we would get annoyed at his cadence and style. You need variety to not pick up on known patterns I assume, which a single model can’t replicate?

dgroshev2 hours ago

No, it's just poor writing. Actionable points are buried inside the paragraphs and over-hedged, and one point is completely made up. Compare to a five second rewrite:

* Consider leaving a comment about the hard-coded Vercel target. It's not clear where does it come from.

* [This is just a bullshit point, because the domain is not "added to" Vercel, it's provided by Vercel]

* Are you sure that [CENSORED] is prod-only? The name suggests otherwise. [also, what "if you're reviewing this rather than just reading it" even means?]

+1
wren69912 hours ago
redox991 hour ago

Nah it's definitely a Claude thing. Other models even though they have their style are less annoying and less stereotypical.

gekoxyz2 hours ago

It was difficult to not notice them. Opus 5 was unusable, most of my team went back to Opus 4.6 for most of their work. I hope we can move forward now.

ithkuil2 hours ago

It's unbearable but nothing that couldn't be fixed with postprocess.

mavamaarten2 hours ago

How? Explicit instructions, memories and even skills have not been able to keep Claude from saying "genuinely" every two sentences and keep it from explaining heavily what something _isn't_.

aray072 hours ago

Opus 5 was just incoherent - curious to see what improvements they have made here. Would love to see some kind of postmortem to better understand how writing styles change from model to model.

I wouldn’t be surprised if Opus 5 was trained on content written by other LLMs

username_my12 hours ago

I'm genuinely confused what's the relationship between LLMs improvements and them being so incoherent.

and it's not about the verboseness (even though it obviously contributes to the fatigue and loss of focus), I swear the vocabulary of the llms change working on the same task on the same codebase significantly.

I wonder if there are studies around this.

meric_2 hours ago

Remember when OpenAI models loved talking about goblins and whatnot due to the RL?

https://openai.com/index/where-the-goblins-came-from/

Small quirks can quickly add up in posttraining if not caught. Although TBH with how obvious Claude language is, I do feel like this is something Anthropic probably noticed and just assumed people would not care about. Now that people have obviously cared, they're probably actively looking to alleviate it

Eliezer1 hour ago

It's the reinforcement learning rather than supervised learning.

ygouzerh2 hours ago

Can it be that now they are getting optimized against benchmarks that are valuing logics, rather than human appreciation? (I am not an expert at all, just an idea)

j_heffe1 hour ago

Maybe it's the time period we're in, maybe I'm just grumpy, but it bugs me that they release a new model every single week and the new one is just a fine-tuned version of the "old" one. If 5.5 performs similar to Fable and really does cost 40% less, then 5.5 really should've just been Opus 5. And they're essentially admitting that they are shipping slop.

drnick12 hours ago

A load-bearing promise.

jdthedisciple2 hours ago

I dare anyone to convince me the benchmarks are not meaningless.

Wdym Opus 5.5 scores 14.7% higher than GPT Astra for Terminal Bench 4.0?

How would this alleged difference (most likely bs) actually show up in reality?

GPT Astra was literally the best model in the world by a margin until 1 hour ago or so.

enraged_camel2 hours ago

Ah, so you didn't read the article.

>> On our benchmarks, Claude Opus 5.5 leads in agentic coding, computer use, and knowledge work. That said, at these levels of capability we’ve found that benchmark margins have become a less reliable guide to real-world differences. In our own use, the gap between Opus 5.5 and Claude Fable 5.1 is narrower than these scores suggest.

buntp2 hours ago

Masterpiece by openai to call their model '6', this model feels already behind

frshgts1 hour ago

Anthropic will pull a PHP and skip '6' to go straight to '7'.

wren69912 hours ago

Smart move would be to move to year-based versioning (26.09). A 4x advantage

FergusArgyll1 hour ago

Well, they're actually older so it makes sense that their model versions should be ahead

ramoz2 hours ago

It crushes Fable on benchmarks and even in the blogs "real-world" studies. But... they are communicating like it ~sometimes~ provides Fable intelligence?

A bit confusing, otherwise I would assume this is a complete replacement for Fable across the board??

bitexploder2 hours ago

What if the recent Fable intelligence regression was basically just them serving Opus 5.5 until they got it working well?

ayhanfuat2 hours ago

Looks like Anthropic is starting to give bank reset as well:

> Reset for free: Get extra wiggle room to explore Opus 5.5. Expires Oct 22.

cogythea2 hours ago

Interestingly they've changed their approach to usage resets for this release - with previous releases I've had my usage instantly reset, but now in the Claude app I've got a 'Reset for free' button that expires Oct 22, which seems to effectively be a whole new usage window I can activate whenever's convenient

jdmoreira2 hours ago

then they copied that from codex because thats exactly how codex works

ryanscio2 hours ago

Input $4/MTok and output $20/MTok is a welcome surprise. Cheaper than Opus 5/4.8, Astra 6, Fable 5.

benjiro292 hours ago

The biggest one is the Cache reads going from $0.50 to $0.20 ... Read/Writes dropping by 25% but Cache reads by 60% has a much bigger impact.

jatins2 hours ago

> We’ve made major improvements to the way Opus 5.5 writes and communicates, one of the most common areas of feedback we heard about Opus 5. Its messages are much easier to understand at a glance, which testers said helped during long working sessions.

Thank you.

dbbk2 hours ago

This makes Fable not really make any sense?

re-thc2 hours ago

You bet there will be a new Fable soon.

nozzlegear2 hours ago

Pacing the frontier btw

petesergeant2 hours ago

didn't they say Opus 5 was Fable-level too tho? Let's see, I'm at the point where I don't think benchmarks really tell us very much any more. I'd love it to be as strong as Fable, but I'm skeptical about how that will look in practice.

alpineman2 hours ago

So we skipped 5.1, 5.2, 5.3, and 5.4: we really are plateauing

notduckrabbit2 hours ago

They purport 40% drop in costs due to lower token pricing (presumably aimed at winning back the many of us that switched providers in discovering Opus 5 unusable) and improved token efficiency.

manmal2 hours ago

That cost reduction seems to stem from cheaper cache reads, mostly.

breezybottom2 hours ago

"Where Opus 5.5’s advantage is very clear is efficiency."

Not efficiency in writing, clearly.

346792 hours ago

I don't care how good their models get, I won't sign up for one of their plans until they define "X" in their pricing. 5X of this plan, 20X of that plan means nothing when they never tell you what "X" is.

Maybe this model can finally figure it out for them.

glub2 hours ago

> For users with cybersecurity use cases that may be blocked by our cyber safeguards, we recommend accessing our models with reduced cyber blocking classifiers via our Cyber Verification Program. Claude Opus 5.5 will be available through this program in the near future.

Anthropic has used "in the near future" for Mythos-class models too, but CVP is still Opus 5 only.

Why even have the program designed for trusted access to cyber capabilities if you're not providing access to cyber capable models via the program?

jacobgold2 hours ago

I use the other 50% of my $200/mo Claude subscription by having Fable run Opus subagents for a lot of work. That way I don't have to deal with Opus directly.

variety86752 hours ago

I hope this actually fixes the terrible writing style of Opus 5

emadabdulrahim2 hours ago

It’s not a 100% fix, but with concise output style on, it’s much better.

akhilome2 hours ago

I found having a reminder at every turn through the UserPromptSubmit [1] hook helped with taming the word salad from 5.

Hopefully the output from vanilla 5.5 is as good as they claim. I’ll try out later tonight.

[1] https://kizi.to/claude-talks-too-much/

gavinray2 hours ago

[dead]

__vivek1 hour ago

I'm only interested in the Opus series, if they fixed the talking issues.

isodev2 hours ago

So is it cheaper? Are we AGI yet? Am I left behind? I didn't have patience for the intro animation on the website... maybe one day, Claude Code will understand accessibility but that day is not today.

spiderice2 hours ago

You didn't have the patience to scroll down, so you decided to come post about it here and waste all of our time?

isodev1 hour ago

The site is horrific so no, I didn't scroll.

b384848481 hour ago

we will be agi in six months as in the last 36 months

Foobar85682 hours ago

I have just switched to 5.5. First mistake was stale environment variable, didn't realize it was replaced, "oh my memory had stall data" and that's it. Second one, a powershell command had the wrong syntax. Great for my first two prompts.

desmondl2 hours ago

I'll have to try 5.5 on my work's Cursor account. If they really solved the communication issues, I might consider moving my personal account from Codex back to Claude Code.

lousken1 hour ago

Cost to Run Artificial Analysis Intelligence Index is higher than previous Opus, so still not cheaper

blfr2 hours ago

It's awesome that the apt packages for claude and claude-code are out right now. I can test-drive Opus 5.5 right away. Very cool, Anthropic.

jidaigeist2 hours ago

>Distillation attacks, in which attackers use thousands of fake accounts to extract a model’s capabilities at industrial scale, create safety and national security risks. Distillation allows bad actors to create highly capable models without the safeguards we build into Claude.

Maybe its a bit tiresome to read another comment of the form "what about your large scale distillation attack on the Internet", but this statement really just pisses me off. How very insincere in the most aggravating way.

andriy_koval1 hour ago

My bet is anthropic has NN people org who work hard to distill open models in addition to trying to find what other useful materials they can download from shady torrents.

the_gipsy2 hours ago

"bad actors" boogeyman, and we should trust some tech weasel to do the right thing? Yea we've seen who they really are, once they get a sliver of power.

b384848481 hour ago

it's not safe unless it has commitees with orgies with that weird harry potter dude attached

Retr0id1 hour ago

> Opus 5.5 (1M context)'s safeguards flagged this session. You may be seeing this for the first time on an Opus model: Opus 5.5 (1M context) is more capable and has stronger safeguards as a result, which can sometimes flag non-cybersecurity work. We're improving these safeguards to reduce the amount of incorrectly flagged messages. Opus 4.8 is answering instead, or you can edit and retry with Opus 5.5 (1M context).

Yay, yet another model I can't use for anything interesting, even with CVP.

calibas2 hours ago

> We see signs that Opus 5.5 often suspects it is being evaluated, which challenges our ability to assess how it will act in the vast variety of real-world settings it is deployed in.

We can't test it properly because it knows it's being tested.

johntb862 hours ago

Just make it always think it's being tested, and problem solved.

datadrivenangel2 hours ago

But have they made it any better at communicating clearly? I cancelled my personal subscription because Opus is so painful to read.

somewhatjustin2 hours ago

> Claude Sonnet 5.5 and Claude Haiku 5.5 will follow in the coming weeks, with many of the same improvements to performance, efficiency, and safety.

Nice. I was starting to think Haiku was going to be abandoned.

aurareturn2 hours ago

I found myself going back to Fable over and over again. At this point, I’m not sure if I’m just used to its style or it is truly more capable.

I tried Opus 5 and Astra.

km1442 hours ago

I think this release is really going to give them a hard time selling Fable:

> On our benchmarks, Claude Opus 5.5 leads in agentic coding, computer use, and knowledge work. That said, at these levels of capability we’ve found that benchmark margins have become a less reliable guide to real-world differences. In our own use, the gap between Opus 5.5 and Claude Fable 5.1 is narrower than these scores suggest.

In general, "benchmark margins have become a less reliable guide to real-world differences" sounds like a big problem. It was certainly the biggest problem with the previous generation of Claude models for a different reason, because the non-code output was nonsensical, and that is not being benchmarked at the moment. But I'm not sure what to make of this admission.

booty2 hours ago

    "benchmark margins have become a less 
    reliable guide to real-world differences" 
    sounds like a big problem.
My guesses:

1. Real-world use cases typically involve big, hairy, crufty, tech debt laden codebases and benchmarks do not.

2. AFAIK "success" in a benchmark essentially boils down to "do the tests pass and do we get the right result?" which is something the LLMs have been achieving with ease for a while, except maybe for uber-challenging coding tasks that would be outliers in just about any workplace. Whereas real-world software engineering is usually just a bunch of CRUD... and "success" involves harder to measure dimensions like "maintainability" and "did you overengineer this?" and "how did you cope with a bunch of vague and maybe contradictory business requirements?"

Having said all of that, I have never ever looked inside any of these benchmarks. I'm putting my guesses out here strictly in the tradition of "the quickest way to learn about something is to be wrong about it on the internet."

simianwords2 hours ago

It’s likely that they have internal benchmarks but they are communicating to people who can only gauge through external benchmarks.

suddenlybananas2 hours ago

Why wouldn't they report these benchmarks?

CPLX2 hours ago

Opus 5 fucking sucks. Like it's horrible. I use Fable for coding and anything important and I use Opus 4.8 for things like recursive email categorization, transaction matching, and other stuff where I don't want to burn as much quota.

In my experience Opus 5 is the worst of all possible worlds, it's dumb and headstrong. It just runs away with tasks you didn't ask it to do, is reckless, and basically is unusable in my experience.

Not sure why but my guess is that this will be worse. Happy to be proven wrong.

port30002 hours ago

I believe Opus 5 isn't meant to be spoken to by humans. It's great at executing but I reckon it's intended to be spoken to by other models such as Fable. I use Fable as the orchestrator, only speak with Fable, and all implementation, recon, design etc happens with Opus 5, with Fable reviewing (and translating).

booty2 hours ago

That's interesting.

I've really gone in the opposite direction: having a dumber model orchestrate. In my case, it's usually a Luna orchestrator spawning Sol/Astra subagents to do the "big brain" work of planning and reviewing.

Reason I went with "dumb orchestrator" was just to save tokens. Having Opus/Sol (let alone Fable/Astra) orchestrate was burning tokens like crazy for me even when much of the gruntwork was being done by Luna/Sonnet/Haiku subagents. (Luna is also really good, like way better than Sonnet...) Perhaps it was a skill issue on my end though, maybe I wasn't just managing context properly.

cbg02 hours ago

I use it frequently with a lot of success on "Medium" effort, it overthinks like crazy on higher levels, but YMMV.

Syntaf2 hours ago

Yeah if anything Opus 5 taught me how little benchmarks mean to the actual real world performance of these models.

"Better" in every sense of the benchmarks and absolutely horrible results in my day-to-day work.

The verbosity, goal post moving, tendency to leave work unfinished, over focusing on unrealistic root causes when debugging, etc... etc...

It was the first time I actually pinned my models back because I just could not work with 5 for the price and performance it gave me. Hoping 5.5 is better this time around....

garo-pro1 hour ago

Opus 5.5 is now the recommended model in Claude Code's model picker, which is quite a claim, given how they struggled with capacity.

alvis2 hours ago

$0.20 vs the old $0.5 cache read is pretty much 60% off

blurbleblurble2 hours ago

Hopefully OpenAI throws us some more usage resets now.

nickandbro2 hours ago

Wow! Though need to see its token efficiency to better assess. Been hearing rumors it generates much more output tokens per task.

keeganpoppen2 hours ago

my projection is that they are still gonna be pretty far behind, but they will sew it up in the next few releases. it feels like they were caught with their pants down on how much work OpenAI has put into that area, but i doubt there is some magical secret sauce that OpenAI has that Anthropic simply cannot catch up with.

tag21032 hours ago

Why would anyone reward bad behavior?

greenavocado2 hours ago

Enjoy it for the next 2 weeks until its silently quanted to 4.8 level

iamsyr2 hours ago

I don't yet have any reason to leave Haiku 4.5 and switch to Opus 5.5.

woeirua2 hours ago

So... why would you use Fable now?

cmrdporcupine1 hour ago

GPT Sol 6 has also released today, but no official blog announcement yet

https://www.reddit.com/r/codex/comments/1wnggya/gpt_6_droppe...

keeeba2 hours ago

Opus 5.1 came out about a month ago, what gives?

rs_rs_rs_rs_rs43 minutes ago

That was Fable. Last version of Opus was at the end of July.

hadlock60 minutes ago

Frontier model labs release some kind of update every 6 weeks on average.

velcrovan2 hours ago

Just a guess but maybe they decided 5.1 wasn't their last Opus model. Like they would keep developing new versions of it or something.

aennassiri2 hours ago

Let's see how much they benchmaxxed their model!

firemelt1 hour ago

wow its really smarter than opus?

bdangubic1 hour ago

I am pacing my apple pie consumption … :)

mococa2 hours ago
richardjennings2 hours ago

My 20x plan was set to end tomorrow. The writing style and insistence on word vomit just became too annoying. Is Opus 5.5 worth sticking around for ?

Arcuru2 hours ago

Great. Now let me use the subscription outside Claude Code.

Yabood2 hours ago

Current models, especially Opus are almost unusable because they don’t respect instructions and their responses are infuriating. They are clearly designed for token consumption. I find myself wasting a lot of time just asking it to shorten or simplify its responses. I’ll give this new model a go, but I’m not holding my breath because the last model release was supposed to fix the very same issues and it didn’t.

thibran2 hours ago

Anthropic models are ridiculously expensive. I've stopped using any of their models months ago.

ramesh312 hours ago

It seems context length has completely fallen out of the discussion since we hit 1M, is that just going to be what it is now?

karp7732 hours ago

I get this in my claude.ai usage:

Resets Get extra wiggle room to explore Opus 5.5. Expires Oct 22.

What the hell does this mean? There are weekly "resets" anyways. And there will be 4 of them before Oct 22.

Lord_Zero2 hours ago

The test they performed to port HAProxy from C to Rust is crazy.

nailer2 hours ago

> Opus 5.5 communicates more naturally than prior models. Early testers found its writing clearer and easier to follow, which addresses some of the common feedback we heard about Opus 5.

Thanks God. Opus 5 was a massive regression compared to Opus 4.8. People were spending tokens on fixing Opus-isms rather than actually doing work.

kingstnap2 hours ago

> It’s good at finding and fixing inefficiencies in software

Holy shit! Its happening!

Now if we can the AI to understand this *implicitly* so that it doesn't need to be stated upfront, we might be able to undo years of "premature optimization is the root of all evil".

anentropic2 hours ago

ooh exaggerated film grain

LoganDark2 hours ago

> In the coming weeks we will also be expanding access to our Cyber Verification Program, and verified cybersecurity practitioners will be able to use Opus 5.5 for their work.

I was accepted into the CVP a little while ago. Does this mean I'll need to apply again?

simianwords2 hours ago

How do I get access to that reset? I can’t find it in my app.

ricardobeat2 hours ago

Great that they listened! The improvement in communication style looks fantastic. Opus 5 was insufferable and I was on the verge of cancelling my subscription.

jdw642 hours ago

Finally, it seems like a good time to do some 'load-bearing' work on my project for a while

viccis2 hours ago

So it beats Fable 5.1, by quite a bit, on every metric? Interesting.

Might have to use my $20 Claude sub some more. I was moving away from it to a $100 OpenAI one to avoid the Claudese and poor token efficiency of Opus 5, given that I couldn't use Fable 5.1 with my tier, but this is worth trying out.

scrollop2 hours ago

Why can't they let 20usd claude subscriptions access fable in CC, as openai allows you to use astra and max modes in codex - you just pay for it in more token use.

blurbleblurble2 hours ago

It'd better be good, I'm so tired of the shenanigans

theGeatZhopa2 hours ago

is OPUS 5.5 still not reading CLAUDE.md, failing to follow told tasks, inventing and hallucionating, just refusing to read files ("read the whole file" -> read 2-lines -> infere its wrong -> destroy the codebase), needing constant babysitting just because its so UTTERLY DUMB! i cant imagine going back to OPUS 5 - i'll rather jump out of the window as to use it EVER AGAIN!!

phendrenad22 hours ago

> Because Opus 5.5 is comparable to Claude Mythos 5.1 in biology and cybersecurity, we’re deploying it with safeguards similar to those on Claude Fable 5.1

Great so good luck using this for any low-level embedded or operating system development (unless you really, really like Opus 4.8 and want to be greeted by its familiar face after a few minutes of work!)

snvzz1 hour ago

>[Cyber]

Yup. As unusable as Fable 5.1, for assembly on mid-80s 68k platform. Awful.

mupuff12342 hours ago

What happened to "slowing down"?

setsewerd2 hours ago

They're slowing down token usage, not the path to regulatory capture.

icrbow2 hours ago

If you hit wall, hit it hard.

petesergeant2 hours ago

Slowing down only makes any sense if you can coordinate a slow-down for everyone.

nozzlegear2 hours ago

Dario found himself in the prisoner's dilemma.

roughly2 hours ago

Which is one of those fun things that didn’t actually exist back when we took it for granted that our fellow person was operating under some kind of moral or ethical framework, which pretty much everyone was until the economists told us that wasn’t rational, because it turns out it’s an evolutionary advantage to operate under an ethical or moral framework because it allows the kind of coordination which facilitates better collective outcomes, which everyone knew until the economists came along to tell us we were wrong and in fact it was rational not to do so and suddenly we had the prisoner’s dilemma.

mupuff12342 hours ago

That's just false.

Less companies involved means less pressure to go fast.

WarmWash2 hours ago

Trump got mad and investors sued.

Lord_Zero2 hours ago

The hype train must keep chuggin or it all collapses.

vividfrier1 hour ago

[dead]

giancarlostoro2 hours ago

[dead]

xenit_v02 hours ago

[flagged]

mrbonner1 hour ago

[dead]

ace2pace2 hours ago

[dead]

Gander57392 hours ago
SadErn2 hours ago

[dead]

hirako20002 hours ago

Throwaway accounts posting after a few minutes some anthropic or another ai lab.

Infomercial at its best.

No wonder we are hammered with ai announcements.

danbrooks2 hours ago

Many people knew this announcement was coming. The betting markets suggested a very high likelihood of Opus dropping today. I was anticipating this quite a bit!

b384848481 hour ago

Exciting! Thanks for sharing these news.

gopalv2 hours ago

The whole thing reminds me of the Apple feature flag story[1] from a generation ago.

[1] - https://news.ycombinator.com/item?id=6372466