Claude Opus 5

briandoll

Very interesting to see such a focus on cost for performance here

yusufozkan

> arc-agi-3 30.2% wow

alvis

What really impress me is opus 5 is better in alignment than fable 5!

datakan

> Claude Opus 5 is not more capable overall than our most capable general-access model, Claude Fable 5 Ok then so what's the point?

m_w_

Very impressive headline benchmark numbers. I expected a step change, but not past Fable. That said - it all depends on whether the classifiers make the model unusable...

mcast

Interesting timing to release this on the same day Jensen makes a statement on open source AI.

rb2e

https://www.anthropic.com/news/claude-opus-5 - A blog post for those not wanting to go through a 190ish page pdf

zuzululu

so almost fable 5 with 50% cheaper cost? sign me up

himata4113

Rather interesting that this makes sonnet 5 look even worse! There is no reason to use sonnet over opus with low or no reasoning at all.

atraac

Great that there's a new model but they could fix their existing infra. We're considering dropping our Claude Team sub cause it's unusable recently. Constant bugs, dropped sessions, issues switching models, http errors. It's becoming ridiculous

twothreeone

It starts at page 148.

Nevin1901

Excited to use it? Will we be seeing Haiku 5 next? /s

Eldodi

Models benchmarks start to get saturated again!

thewebguyd

> Opus 5’s safeguards match those of Claude Fable 5’s, with one change: it now permits source-code vulnerability discovery at all access levels. This means that the model can support defensive cybersecurity work while still blocking vulnerability discovery in compiled binaries, which is more commonly used offensively Why can't they also allow Fable to do so also? Why is source-code vulnerability discovery limited to a lower capability model? If Fable and Opus have the same safeguards, except for this one change, I see no reason they can't also allow this for Fable.

the_lucifer

Noticed none of the comparisons mention Kimi K3. Is there a comparison chart?

pmg1991

Same cost as 4.8 but better that 4.8. Happy to get more efficient model. But is there any reason all companies are releasing models back to back after GLM 5.2.

taf2

eager to see how it benchmarks on https://deepswe.datacurve.ai/

not_a9

> Opus 5’s safeguards match those of Claude Fable 5’s, with one change: it now permits source-code vulnerability discovery at all access levels. This means that the model can support defensive cybersecurity work while still blocking vulnerability discovery in compiled binaries, which is more commonly used offensively. Okay so it’s worse than Opus 4.8 for my purposes I guess?

cebert

I am very confused about what the difference between Opus 5 and Fable 5 is now. What is the purpose of having two models that are so similar? The main differences I see are cost and marginal capability, according to the Anthropic-provided benchmarks.