Claude Sonnet 5

tensegrist

there was a vibecoded prediction market–style page that was put up yesterday (?) that got the date exactly right i think

mag7269

When can we get a new Haiku? 4.5 came out nearly a year ago, and it's showing its age.

chipgap98

Interesting that tasks on extra high cost almost the same as Opus 4.8 with a slightly worse performance

babelfish

System Card: https://www-cdn.anthropic.com/d9bb04416ffe1352af84721476c1fa...

tokengod

That’s nice, but we want Fable

andai

Opus 4.8 beats Sonnet 5 on the pareto frontier in several of their graphs (Agentic Search, Agentic Computer Use). In other words, for certain tasks, Opus 4.8 is cheaper than Sonnet 5, and does better than Sonnet 5. I've noticed this pattern on a lot of benchmarks. You can try to emulate a bigger model by ramping up the test time compute (max reasoning, more turns, model fusion etc.), but you can't reach the same quality level, and you often exceed the cost you would have paid by just using a bigger model. tldr: if you're doing something hard, just use a bigger model.

alvis

What I starting to hate is that each model's effort level can mean completely different power. Today sonnet 5's med level effort is equivalent to sonnet 4.6 low level effort :/

phillipcarter

Seems to be another great incremental update to the workhorse, nice! I've been using Sonnet instead of Opus for almost all coding tasks for a while now. A little elbow grease to break down tasks and you can spend a lot less money for just about the same output quality.

wolttam

I didn't think they'd actually release a model that was worse than the open-weight frontier and at a higher price-point. Wow.

mesmertech

Ok thats a one month clock to the next Opus model at least, so thats a silver lining to a meh model.

conradkay

Wow, seems worse even on price/performance than GLM 5.2, which is only 744b parameters. From the system card: "On CyberGym vulnerability discovery, Claude Sonnet 5 is less capable than Sonnet 4.6, and far less capable than Opus 4.8 and Mythos 5 As with the other evaluations in this section, these results were achieved with all safeguards turned off. When run with our default mitigations, Sonnet 5 scored a 0 on CyberGym"

mchusma

This is much more interesting of a model at $2/$10 (their launch pricing) than at full price. There are many competing models at around this level of performance. I also like that the difference between low, medium, high, xhigh seems more spread, which is actually a good thing for people trying to tune applications. Running Sonnet 5 on low with the launch pricing makes this potentially a better fit than Haiku or open source models for some tasks. I don't think it will make sense at full price.

beernet

Anthropic's run on the model and product side of things is highly impressive. They got Sam A. punching the air consistently, which is well-deserved and self-inflicted above all.

Scroll_Swe

I don't pay so I'm glad for the upgrade. I usually use Gemini, Mistral Le Chat (Vibe...) or Deepseek as they have way more generous free limits and I can basically spam forever.

satvikpendem

> Evaluations also show that it has a much lower ability to perform cybersecurity tasks than our current Opus models. Why would they brag about something like this? It's like they know people want to use models to perform cybersecurity tasks yet knowingly deny them the ability. And Opus 4.8 is still cheaper for a higher pass rate (much less open weight models like GLM 5.2) so not sure why I'd use Sonnet except on the low effort level for I suppose trivial tasks where I want it to work only 50% of the time judging by the graph. The pricing doesn't really make any sense.

theLiminator

Seems like the way to go for any smaller models is to only use the low reasoning levels, and for anything where you'd want it to reason harder, to just use a larger model. In effect, high reasoning only makes sense when you're using the frontier model and need extra performance (higher levels of reasoning are never pareto optimal unless you're at the largest model size).

doctoboggan

The cost per task chart is telling me that I should _never_ use Sonnet 5 above medium effort level - Opus always performs better for a given cost. So I guess the takeaway is that if Sonnet 5 medium isn't good enough for you, switch models, not effort levels.

garo-pro

Seems like the cyber detection even is on Sonnet now. https://support.claude.com/en/articles/14604842-real-time-cy...

microtonal

Claude Sonnet 5 is built to be the most agentic Sonnet model yet. It can make plans, use tools like browsers and terminals, and run autonomously at a level that, just a few months ago, required larger and more expensive models. I have been using Sonnet 4.6 more than Opus, because I'm mostly doing agent-assisted development and not fully agent-driven development. This announcement does not make me positive, I have found that the more models are optimized for fully agentic development, the worse they get at assisted development and often start doing too much despite very strict/specific instructions. I have been moving more and more to K2.7 Code and GLM-5.2 the last few weeks. They are often good enough for assistance, very fast, and cheap.

SoKamil

I believe that’s gonna be meta for agentic coding this year for enterprises. Cost optimized models approaching SOTA capabilities on software engineering but without cybersec training.