Claude Opus 4.1 (anthropic.com)

Tested it on a refactor of Zig code. It worked fine, but was very slow.

as if they wait competitor first then launch it at the same time to make market decide which one is best

None of them seem to have published any papers associated with them on how these new models advanced the state-of-the-art though. =^(

It's definitely a coincidence

This is why you have PR departments. Being on top of the HN front page, news sites, etc matters a lot. Even if you can't be the first, it's important to dilute the attention as much as possible to reduce the limelight your competitors get.

They likely sit on releases ready to go.

There's so many leakers in every lab

Eu auto brands colluded for years to synchronize new tech into their model lines. Could it be the AI SaaS sector is showing its first steps towards "maturity"? /s

Good! I'm glad they are just giving us small updates. Opus 4 just came out, if you have small improvements, why not just release them? There's no downside for us.

I don't think this could even be called an improvement? It's small enough that it could just be random chance

They need to leave some room to release 10 more models. They could crank benchmarks to 100% but then no new model is needed lol? Pretty sure these pretty benchmark graphs are all completely staged marketing numbers since they do solve the same problems they are being trained on – no novel or unknown problematic is presented to them.

"You pay $20/mo for X, and now I'm giving you 1.05*X for the same price." Outrageous!

I will only add that it's interesting that in the results graphic, they simply highlighted Opus 4.1 - choosing not to display which models have the best scores - as Opus 4.1 only scored the best on about half of the benchmarks - and was worse than Opus 4.0 on at least one measure.

I am still very early, but output quality wise, yes, there does not seem to be any noticeable improvement in my limited personal testing suite. What I have noticed though is subjectively better adherence to instructions and documentation provided outside the main prompt, though I have no way to quantify or reliably test that yet. So beyond reliably finding Needles-in-the-Haystack (which Frontier models have done well on lately), Opus 4.1 seems to do better in following those needles even if not explicitly guided to compared to Opus 4.

If I'm using cursor then sonnet is better, but in claude code Opus 4 is at least 3x better than Sonnet. As with most things these days, I think a lot of it comes down to prompting.

It's ridiculously overpriced in the API. Just like o3 used to be.

I feel the same way. I usually use Opus to help with coding and documentation, and I use Sonnet for emails and so on.

Im on the Max plan and generally Opus seems to do better work than Sonnet. However, that’s only when they allow me to use Opus. The usage limits, even on the max plan, are a joke. Yesterday I hit the limits within MINUTES of starting my work day.

I notice that on the "Agentic Coding" benchmark cited in the article Sonnet 4 outperformed Opus 4 (by 0.2%), and under performs Opus 4.1 (by -1.8%).

So this release might change that consensus? If you believe the benchmarks are reflective of reality anyways.

> yet the general consensus and my own experience seem to be that Sonnet is much much better

Given that there’s nothing close to scientific analysis going on, I find it hard to tell how big the “Sonnet is overall better, not just sometimes” crowd is. I think part of the problem is that “The bigger model is better” feels obvious to say, so why say it? Whereas “the smaller model is better actually” feels both like unobvious advice and also the kind of thing that feels smart to say, both of which would lead to more people who believe it saying it, possibly creating the illusion of consensus.

I was trying to dig into this yesterday, but every time I come across a new thread the things people are saying and the proportions saying what are different.

I suppose one useful takeaway is this: If you’re using Claude Max and get downgraded from Opus to Sonnet for a few hours, you don’t have to worry too much about it being a harsh downgrade in quality.

Just more ancedata, but I entirely agree. I can't say that I am happy with Sonnet's output at any point, really, but it still occasionally works, whereas Opus has been a dumpster fire every single time.

I don't doubt Opus is technically superior, but it's not practically superior for me.

It's still pretty much impossible to have any LLM one-shot a complex implementation. There's just too many details to figure out and too much to explain for it to get correct. Often, there's uncertainty and ambiguity that I only understand the correct answer (or rather less bad answer) after I've spent time deep in the code. Having Opus spit out a possibly correct solution just isn't useful to me. I need to understand _why_ we got to that solution and _why_ it's a correct solution for the context I'm working in.

For me, this means that I largely have an iteratively driven implementation approach where any particular task just isn't that complex. Therefore, Sonnet is completely sufficient for my day-to-day needs.

I use both. Sonnet is faster and more cost efficient. It's great for coding. Where Opus is noticeably better is in analysis. It surpasses Sonnet for debugging, finding patterns in data, creativity and analysis in general. It doesn't make a lot of sense to use Opus exclusively unless you're on a max20 plan and not hitting limits. Using Opus for design and troubleshooting and Sonnet for everything else is a good way to go.

With aggressive Claude Code use I didn't find Sonnet better than Opus but I did find it faster while consuming far fewer tokens. Once I switched to the $100 Max plan and configured CC to exclusively use Sonnet I haven't run into a plan token limit even once. When I saw this announcement my first thing was to CMD-F and see when Sonnet 4.1 was coming out, because I don't really care about Opus outside of interactive deep research usage.

That’s very strange. Sonnet is hot garbage and Opus is a miracle, for me. I also don’t see anyone praising sonnet anywhere.

I've found with limited context provided in your prompt, opus is just awful compared to even gpt-4.1, but once I give it even just a little bit more of an explanation, it jumps leagues ahead.

Opus really shines for completing long-running tasks with no supervision. But if you are using Claude Code interactively and actively steering it yourself, Sonnet is good enough and is faster.

I don't believe anyone saying Sonnet yields better results than Opus though, as my experience has been exactly the opposite. But trade-off wise, I can definitely see it being a better experience when used interactively because of its speed and lower cost.

My opinion of Opus is that it takes the correct action 19/20 times, where Sonnet takes the correct action 18/20 times. It’s not strictly necessary to use Opus, but if you have the subscription already it’s just a pure win.

I use opus or gemini 2.5 pro for plan mode and sonnet for act mode in Cline. https://cline.bot

It's my experience that Opus is better at solving architectural challenges where sonnet struggles.

100% opus all the time. Sonnet seems to get confused much faster and need more hand holding in my experience.

Strategy I'm playing with, we'll see how good of results I get, is to prompt Opus to analyze and plan but not implement.

E.g. prompt to read a paper, read some source, then write out a terse document meant to be read by machine not human.

Then switch to Sonnet, have it read that document, and do the actual implementation work.

Opus is superior to understand the big picture and the direction.

Sonnet is great at banging it out.

Could it be nobody wanted to be first and overshadowed, nor the only one left out - and it cascaded after the first announcement? My first hunch, though, was that it had been agreed upon. Game theory I think tells us that releasing same day in the pattern ABC BCA CAB etc would be lowest risk and highest average gain?

If they release before GPT-5, they don't have to compare to GPT-5 in their benchmarks. It's a big PR win to be able to plausibly claim that your model is the best coding model at the time of release.

The finest of AI, probably using electricity/water for 100s of homes can not even beat a very simple children game with millions of texts guides etc. about it.

When can we replace doctors with it?