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Claude Opus 4.8

1011 pointsby craigmarttoday at 4:49 PM805 commentsview on HN

Comments

NiloCKtoday at 5:06 PM

A rambling comment:

I think this is the first time we've had a third minor version bump on a frontier Anthropic model. (I count the 0.5s as major here, because they've been issued non-sequentially and also corresponded to massive capability leaps, eg, Sonnet 3.5, Opus 4.5).

So now the Opus 4.5 family has successors 4.6, 4.7, and 4.8, each posting fairly modest claimed gains. My own experience w/ 4.6 and 4.7 are that I don't firmly grasp any capabilities improvements over my memory of 4.5, but it's all so fuzzy that it's truly difficult to tell.

Maybe my own tastes are saturated now (it's smarter than me?) and I'll never again perceive model progress. Maybe the incrementalism is such that I'd notice immediately if my 4.7 workflows were redirected now to 4.5.

Difficult spot for the labs to be in because, if they have a stronger product, I'd prefer they release it and that I can use it.

But as this dynamic continues, the improvements are going to be less and less legible for end-users, who will complain about the churn-without-payoff, even when the payoff may actually be real.

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xintrontoday at 9:44 PM

Based on personal experience, seeing how Opus 4.6 still provides better (more nuanced, less totalitarian) answers than 4.7 - it's difficult to get exited for 4.8. Is this another "money grab" from Anthropic? Similar output between 4.6 and 4.7 yet 40x tokens. What's the value proposition from 4.8?

colonCapitalDeetoday at 4:58 PM

"Users will find Opus 4.8 to be a modest but tangible improvement on its predecessor."

This is a refreshing attitude!

I've also verified that you can now turn off adaptive thinking in the web UI, which is great. I've had a lot of problems with thinking not triggering and the model producing sub-par output. Glad we can finally turn it off. (I hope being able to turn off adaptive thinking is new, if I could have turned it off at any time that would be embarrassing)

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northern-lightstoday at 4:57 PM

> Not only that, but we plan to release a new class of model with even higher intelligence than Opus. As part of Project Glasswing, a small number of organizations are currently using Claude Mythos Preview for cybersecurity work. Models of this capability level require stronger cyber safeguards before they can be generally released. We’re making swift progress on developing these safeguards and expect to be able to bring Mythos-class models to all our customers in the coming weeks.

Probably more interesting than the 4.8 release.

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simonwtoday at 5:06 PM

I generated pelicans riding bicycles on both thinking level low and thinking level high:

https://gist.github.com/simonw/68560eddb0b268a8417f80ceb7304...

The high one is notably better - the bicycle frame is the correct shape, unlike thinking level low.

For comparison, here's Opus 4.7: https://gist.github.com/simonw/afcb19addf3f38eb1996e1ebe749c...

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senkotoday at 6:34 PM

My fav coding benchmark for frontier models is to build a simple RTS game in one file (js/html/css). Claude Code with Opus 4.8 in ultracode mode nailed it, the best result so far:

https://bsky.app/profile/senko.net/post/3mmwnrkwboc2v

The prompt was: Create a simple but functional real time strategy (RTS) game similar to old WarCraft, StarCraft or Command & Conquer games. The player should be able to build buildings, create units, gather resources and should uncover the whole map. No AI or multiplayer needed. Use simple but nice-looking graphics. No sound. Implement everything in HTML/CSS/JS, everything in a single file (you can use 3rd-party js or css libraries/frameworks via CDN).

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hereme888today at 8:26 PM

Early ArtificialAnalysis.ai results show GPT 5.5 is still the better bang-for-your-buck.

OpenAI solves tasks with about 50% less output tokens.

https://artificialanalysis.ai/?intelligence=coding-index&int...

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onlyrealcuzzotoday at 4:55 PM

Does anyone troll these releases and cherry pick random metrics other companies would cherry pick to show how amazing their models are?

There's like 8 million benchmarks. Every release, every model randomly picks 5-10 where they win in everything except 1, to make it look like they aren't randomly cherry picking benchmarks they probably benchmaxxed for.

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gslepaktoday at 5:03 PM

On page 102 of the system card [1] I'm pleased to see evaluation against "creative mastery".

In our work we asked several frontier AIs to come up with an API we needed. We compared Opus 4.7 and GPT-5.5 (among others). Opus 4.7 came up with the most creative and intelligent API design that pleasantly surprised us, especially given that GPT-5.5 was passing it on various coding benchmarks.

What I noticed is that we don't have a commons benchmark to measure "creativity" and "ingenuity", and in some ways such a benchmark would conflict with the common IFBench benchmark. Yet this is a very important skill when designing systems. I'm glad to see Anthropic putting thought into it, and would love to see a public benchmark for this that other models could compare themselves to.

[1] https://cdn.sanity.io/files/4zrzovbb/website/c886650a2e96fc0...

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silverlighttoday at 5:43 PM

Unfortunately they seem to have straight up broken Claude Code either with this release in the backend or the new CC version. Errors about "can't modify thinking blocks" are bricking long-running sessions: https://github.com/anthropics/claude-code/issues?q=is%3Aissu...

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827atoday at 6:42 PM

Frontier models are mostly past the point of human ability to discern whether they are actually better or worse than predecessors and competitors. I suspect the benchmarks may also be saturated, or at least past their usefulness.

I personally feel that Anthropic doesn't understand what this means for the frontier labs, and moreover that they might be the only frontier lab that doesn't.

1. Google dropped Gemini 3.5 Flash at IO, delaying the release of 3.5 Pro for a bit (they have said its coming). They also released a refreshed Antigravity, and drew special attention to how cheaply they were able to build their toy operating system to play Doom (less-than $1000 IIRC).

2. OpenAI has dumped everything into Codex, is offering double the token limits for the next few weeks IIRC, and is offering business discounts. Their head of Codex has tweeted that 5.5 is "extremely efficient", implying that they aren't actually losing money on any of this.

3. DeepSeek and other Chinese labs have dropped token pricing to the floor, in some situations as much as 99%.

4. Anthropic releases the next generation of Opus, their most expensive public model, without changing its price. In the background, they hype up Mythos, an even more expensive model.

Anthropic has screwed up where they need to be making investments, and the cracks are starting to show. They've marginally underinvested in the Sonnet line of models for almost a year now, and they've critically underinvested in product. Anthropic made bets on the story of the second half of 2026 being: ultra-frontier, ultra-intelligence. In reality, what's shaping up is that the story will be: Companies rolling back AI spend, efficiency, "95% as good for 15% the price", sophisticated high quality harnesses, cheaper models. Anthropic isn't ready for this world.

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XCSmetoday at 5:53 PM

On my tests[0] it does a bit worse, and it's almost 2x expensive than Opus 4.7...

I was surprised to see that it failed a Data extraction test (it gets it right 2/3 times, but one time it randomly returns null for a value instead).

It makes sense a bit that it fails more Trivia/Domain-specific knowledge tasks (I think models are more and more trained towards agentic use-case than general intelligence).

[0]: https://aibenchy.com/compare/anthropic-claude-opus-4-7-mediu...

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eshack94today at 8:47 PM

The Claude Pro subscription is basically useless at this point, in terms of usage limits with respect to the settings required to achieve actual useful output.

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wg0today at 5:12 PM

There is a hole in the boat's bottom due to Chinese models. They might not be as good but they are not bad either or at least I had hard time finding any issues with Deepseekv4 Flash and Pro variants. They get their job done sometimes rarely giving up till they are done what they are after.

So even for enterprise deployments, as the dust settles down, CFO/CTOs might find out that deploying on an internal cluster of GPUs is far more cheaper and reliable for their organisational needs than paying someone else for burned tokens.

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alansabertoday at 5:47 PM

"Our models are more honest" honey the quarterly marketing spin for a ML term has come. Forget "task alignment" now we're going for "truth index". I suppose this is the only way to generate hype when you're selling/releasing the same product over and over again.

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pbmangotoday at 4:55 PM

I can't help but think of Iphone updates since about 2018. The thinnest, fastest, longest battery life Iphone ever. It seems mostly the same and I probably won't be able to tell other than the name, but everyone buys it anyway.

This is good psychology for the labs. When Buffett invested in Apple he loved citing how most people would rather give up their second car than their Iphone.

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SimianScitoday at 4:58 PM

There is an obvious shift in sentiment amongst users, at least here in the US. I feel it myself, even as a proponent of AI tools, the bloviating and language that these companies use in these release articles are starting to wear thin on my patience.

Its possible we might just be witnessing a shift in fashion, where this type of sentimentality was more acceptable when it was novel and new, but now it just appears out of touch.

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irthomasthomastoday at 5:44 PM

Why does anthropic change the set of benchmarks they use with every new model release?

https://www.anthropic.com/news/claude-opus-4-7

https://www.anthropic.com/news/claude-opus-4-6

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square_usualtoday at 5:09 PM

Buried lede:

> We have increased rate limits in Claude Code to accommodate the higher token usage of higher effort levels

lordmauvetoday at 5:27 PM

Given DeepSWE just blew apart the SWE-Bench Pro benchmark and handed a 14-point lead to GPT-5.5, it looks pretty bad that they've listed SWE-Bench first in the model release and no DeepSWE. Like, this isn't obviously an answer.

Or maybe it is, but publish the DeepSWE numbers so we can see for ourselves.

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dudeinhawaiitoday at 6:43 PM

This is the first time I saw a model pop-up on HN and didn't really care. Model exhaustion? It looks interesting but not exciting.

While I'd normally _love_ incremental improvements --- I think the recent ones are far too minor to get excited about or change up a workflow. Besides, benchmarks tend to exaggerate the gap between versions.

At this point I'd almost rather Anthropic wait and really wow us with a 5.0 release -- something that improves across the board, feels less uneven, and is performant enough that people can actually put it through its paces without constantly rationing usage.

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dangoodmanUTtoday at 5:19 PM

> The Messages API now accepts system entries inside the messages array. Developers can update Claude’s instructions mid-task without breaking the prompt cache or routing the update through a user turn. This can be used in a given harness to update permissions, token budgets, or environment context as an agent runs.

Biggest deal imo

setnonetoday at 5:17 PM

Claude's 4.6 - 4.7 transition made me discover codex, and with gpt 5.5 there is no way i'm going back

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redfloatplanetoday at 7:09 PM

This made me laugh. Training Opus 4.7 on business skills caused it to sometimes exhibit dishonest behaviour, and not training 4.8 on those skills removed it. From the system card:

> 6.2.5 External testing from Andon Labs Andon Labs reviewed the behavior of Claude Opus 4.8 in their simulated Vending-Bench 2 retail-management evaluation, as reported in the Capabilities section of this system card (see Section 8.13.5). Although they did observe some unexpected capability failures, they did not find clear instances of the kind of concerning in-game behaviors that were discussed in other recent system cards.

> What might have led to these differences? We monitor and investigate the effects of different training environments on alignment; Claude Opus 4.7, for example, had training that focused on business skills and robustness against adversarial agents, but we discovered that this training inadvertently contributed to misaligned behavior including dishonesty. We therefore removed it for Opus 4.8.

> Thus, Opus 4.8 did not show the same misaligned behaviors as Opus 4.7 in Vending-Bench, but also had reduced business success due to being more susceptible to scammers and being less able to negotiate good deals with other agents. We are currently working on training to improve business capabilities while maintaining aligned and ethical behavior.

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conceptiontoday at 6:01 PM

Probably explains why Opus was trash for the last week - https://marginlab.ai/trackers/claude-code/. Curious if the new baseline will rise now in-line with the new benchmarks.

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protoman3000today at 8:16 PM

Opus 4.8 says to take the car. 4.7 said to walk.

“I want to wash my car. The carwash is 50m away. Should I take the car or go by foot?”

https://claude.ai/share/5f7f738a-5f29-48ff-9807-9a2dd37fb405

https://claude.ai/share/ecd14393-9d42-4527-ae0c-89f3d05216c8

ethanpiltoday at 6:13 PM

The table comparing eval scores shows the following:

Agentic Terminal Coding (Terminal-Bench 2.1) Opus 4.8 74.6% GPT 5.5 78.2%

Then, when you scroll all the way down to the bottom Footnotes section it says

"Terminal-Bench 2.1: We reported scores for all models using the Terminus-2 public harness. GPT-5.5’s reported score with the Codex CLI harness is 83.4%."

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mesmertechtoday at 5:23 PM

/model claude-opus-4-8

seems to work but idk why they never set it so you can see it in the /model list.

"what model are you

I'm Claude Opus (claude-opus-4-8), running in Claude Code."

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user-today at 7:48 PM

Bash(echo "hello"; pwd) ⎿ hello /Users/username/Work/Github/project

Bash(echo test123) ⎿ test123

  Read 1 file, listed 1 directory (ctrl+o to expand)

 Bash(echo "checking output works")
  ⎿  checking output works

  Read 1 file (ctrl+o to expand)
  ⎿  API Error: 400 messages.3.content.56: `thinking`
     or `redacted_thinking` blocks in the latest
     assistant message cannot be modified. These
     blocks must remain as they were in the original
     response.

Very inspiring improvements. DIssapointing result for a code review i expected to see after my 30 min walk
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assoriumtoday at 9:29 PM

It refused to work for me. Literally said, you can google it. AGI achieved it seems

IFC_LLCtoday at 6:05 PM

Ugh...

Invalid request The request couldn't be completed. View details API Error: 400 messages.1.content.7: `thinking` or `redacted_thinking` blocks in the latest assistant message cannot be modified. These blocks must remain as they were in the original response.

I would rather not. 4.6 was fine. 4.7 got to be fine 1 week after the release. Now 4.8. No difference, same thing.

But the app is broken and nothing works. So now I have to regress to different clients and wait it out while it becomes workable again.

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james_markstoday at 4:57 PM

> One of the most prominent improvements in Opus 4.8 is its honesty. We train all our models to be honest—for instance, to avoid making claims that they can’t support. But a general problem with AI models is that they sometimes jump to conclusions, confidently claiming to have made progress in their work despite the evidence being thin. Early testers report that Opus 4.8 is more likely to flag uncertainties about its work and less likely to make unsupported claims.

Would be awesome if true

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jtrntoday at 7:14 PM

Initial testing feels better than 4.8 And the knowledge cutoff claim of January 2026 seems to check out since it was able to "remember" without search about the double-tap killing of a drug smuggler by the US Army in late December.

hmokiguesstoday at 9:10 PM

They must have been A/B testing this with 4.7 lately, I noticed it changed from its normal mode in a way that matches a lot the just released 4.8

londons_exploretoday at 5:48 PM

My guess is anthropic is doing reinforcement learning based on user sessions.

However, doing so relies on the production model staying vaguely close to the model being trained.

To ensure that, frequent releases are needed. I forsee that they might end up doing daily releases and perhaps not even telling anyone at some near future point.

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swader999today at 7:39 PM

Used it for a couple of long running prompts so far. Had to restart one that bonked on API errors. Of note, I really like the straight forward candor its using. 'More honest' than previous models is playing out in what its saying to me. Telling me straight up where it failed, where gaps are. I like it so far.

tarrudatoday at 5:12 PM

> One of the most prominent improvements in Opus 4.8 is its honesty.

Does that mean it no longer deletes or changes tests to make it pass?

jmward01today at 5:04 PM

Meanwhile haiku is on 4.5 and sonnet is on 4.6. It is clear where they are not making money.

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rkuskatoday at 7:42 PM

Thinking on max is broken on 4.8 for me, getting many:

⎿ API Error: 400 messages.1.content.17: `thinking` or `redacted_thinking` blocks in the latest assistant message cannot be modified. These blocks must remain as they were in the original response.

From /code-review max.

babelfishtoday at 4:59 PM

So GPT 5.6 tomorrow, then?

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rahimnathwanitoday at 6:26 PM

Can anyone explain how this is possible?

  Developers can update Claude’s instructions mid-task without breaking the prompt cache or routing the update through a user turn. This can be used in a given harness to update permissions, token budgets, or environment context as an agent runs.
Does this means the instructions are no longer just something in the early part of the conversation? (If they were, changing them would invalidate the KV cache. no?)
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generalizationstoday at 4:58 PM

Hoping that one day they'll let me go through the identity verification process so I can use it again.

Tried to upgrade my subscription, triggered identity verification, verification fails to even start, and now I can't even use the subscription tier I'd already paid for.

Tenoketoday at 5:13 PM

Claude Code has been wonderful for work and the frequent improvements are nice, although with Mythos being used by others ages ago and new versions for the public still being bellow that, it's hard to not feel like the underclass already.

nikolaytoday at 5:27 PM

Give us Mythos! This piecemealing doesn't help Anthropic at all, especially psychologically! They are playing a dangerous game, and I see many people leaving Claude Code for good - both due to the subsidy games, and for Anthropic not dogfooding and using unreleased models internally and giving us subpar ones. Benchmarks are nice, but the real-world experience is quite different - neither can you notice these slight improvements, nor are competitors that much worse based on some generic benchmarks.

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lxxpxlxxxxtoday at 5:51 PM

My experience with these new releases is that the gains in performance are negated by the price increases and it seems like:

Performance gains: 1.2x Price increases: 1.8x

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techtuatetoday at 6:15 PM

Looking at the comments in this group, I'm not the only "stupid" one who hasn't noticed any discernable improvement in quality across the newer models. In fact my Claude code on re-login switched to Sonnet 4.6 and the vibe coding quality (with Opus 4.7 assisted prompts) has been good enough for me to lazily persevere with Sonnet for coding. Having said that I'm now on Opus 4.8 and will gladly come back here and eat humble pie should my opinion change. PS: Since my goal is embedding the best AI in B2B SAAS products, the key differentiator is not to use the shiniest Claude version (too expensive anyway) but to build a client aware RAG to enable bespoke learning and to use the right AI for my product - a combination of Gemini 3.0 Flash (image and not bad at reasoning), Grok (reasoning) work for me. Would love to hear more ideas (especially on open source as I'll look to cost optimize when I hit scale)

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cgg1today at 8:46 PM

I find it surprising that the gap between tool usage and non-tool usage in HLE is relatively small (~10%) but the absolute numbers continue to go up

rumblefrogtoday at 5:03 PM

Wonder if we reached a plateau with the model improvements?

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tarikytoday at 7:50 PM

I believe analogy with smartphone will be best for this case.

In 2010s iphone was the king, all those Chinese devices ware cheaper but not even close to smoothnest and usability of US tech, now after 15 years later everything is changed, now iphone feels like old grandpa to Chinese tech. Same will happend to LLM's just much faster.

cedwstoday at 5:14 PM

I'm very suspicious of these same price model launches. It feels like they're benchmaxxed so they can put everyone on them and reduce their compute costs behind the scenes. If the model were genuinely better why wouldn't they charge more for it? Charging the same for something better is a race to the bottom.

Opus 4.7 wasn't noticably any better for me, I still use 4.6 because it's cheaper.

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