I went to 4.7, didn't have a choice, found it unsatisfactory, then Claude quietly added in the option to use 4.6, so I'm back on 4.6, and I'm not the only one in my company.
I had far more hallucinations with 4.7 than 4.6.
I'll try it again after a few more months for them to get it right, but 4.6 is what changed my mind on LLMs as a tool, and 4.7 felt like a step backwards, so for now I'm sticking with something that has delivered me value, instead of arguing with a model ostensibly better that was making shit up 1 - 2 times a day. It was really disappointing.
I can give examples if needed, I screenshotted the most aggravating ones, but what worries me is which ones I didn't recognise.
Opus 4.7 went through a major degradation a few weeks ago (way more hallucinations and rabbit holes than usual). Anthropic fixed it. Give it another shot.
Opus 4.7 seems very smart but the adaptive reasoning makes me always uncertain how hard it is actually trying. And it is far too argumentative. It seems to think it HAS to contradict you in ever response.
I have stuck with 4.6. I fully believe 4.7 can be smarter for truly complex and long running agentic use. But I prefer the more direct, literal mechanistic style and 4.6 seems to be peak Opus for that.
Same. 4.7 intelligence is significantly worse than 4.6 on ALL 3P Harnesses. So only on Claude Code and Anthropic API/Subscription you get decent performance but on every other Harness and/or Cloud Provider inference (Bedrock) it performs worse than 4.6 on almost every task. This is not just anecdotal, i've talked to many colleagues from AWS, Microsoft and so on and they all agree that something fishy is going on.
I switched back to even Sonnet 4.6 in Claude Code over Opus 4.7. Every day or two I try a new task on Opus 4.7 and regret it.
Looking now I see that "Opus 4.6 Legacy" is an option that was not there before, so maybe Anthropic noticed that others are having the same difficulty.
I was recently talking to someone about that! I wasn't sure if it was my imagination, but I felt like Opus 4.6 was way more diligent about looking things up online and making sure that its response was accurate. While Opus 4.7 seems content to just throw out an answer as quickly as possible with little care for accuracy; I started to always remind it to do an online search and to double check its work, to the point where I had to add a custom memory.
I switched back to 4.6 thinking, as most did, 4.7 introduced some jankinesss to it. I switched back soon enough to 4.7. I think I might've adapted myself to what and how 4.7 does things. 4.6 felt a step backward.
4.7 is better if your spec is clearer. 4.6 is better if you give it more freedom doing it's tasks. 4.6 felt it'll steer off often if you give detailed specs than 4.7 though, so perhaps that's it
How does their versionimg work? Because I've assumed that they're constantly tweaking their system prompts, I'm hoping in a couple of months, 4.7 will be improved over my first impressions- I caught significant hallucinations, something I'd rarely experienced with 4.6, if at all, I honestly can't remember one - but what I worried me was thebout the hallucinations I didn't catch.
I still use 4.6 if I need Opus. It's mostly GPT-5.5 for me. Only if I know it cannot do some thing like push without running the tests (because AGENTS.md said so), I switch to 4.6.
Although GPT's been acting weird since Thursday...
Switched back when 4.7 had an issue last week and it was wayyy faster. I assume mostly because a lot of people have moved off but might consider using it more just for the speed boost.
4.7 turned out to be a disaster in multilingual settings, so I sticked to 4.6 so far. 4.7 seemed to be optimized for (very specific slice of) coding at the expense of everything else.
i use 4.6 and i've configured advisor to be on 4.7, so, when something's more complex the advisor can help. at least that's how i do with claude code, not sure of the others have implemented the concept of advisors.
I went to 4.7, didn't have a choice, found it unsatisfactory, then Claude quietly added in the option to use 4.6, so I'm back on 4.6, and I'm not the only one in my company.
I had far more hallucinations with 4.7 than 4.6.
I'll try it again after a few more months for them to get it right, but 4.6 is what changed my mind on LLMs as a tool, and 4.7 felt like a step backwards, so for now I'm sticking with something that has delivered me value, instead of arguing with a model ostensibly better that was making shit up 1 - 2 times a day. It was really disappointing.
I can give examples if needed, I screenshotted the most aggravating ones, but what worries me is which ones I didn't recognise.
How did you manage to do that?
/model command returns only 4 choices for me: Opus 4.7, two Sonnet options and Haiku.
I’ve read (but haven’t tested yet) that you can still enable Opus 4.6 with:
That gets billed as extra usage apparently:
/model claude-opus-4-6[1M]
In my model I have also opis 4.6.
Maybe this is becaus I'm on api pricing? (All new contracts for corps are pushed to that by Anthropic).
env var
This works, thanks :)
For anyone else who may want this, use: export ANTHROPIC_MODEL=claude-opus-4-6
Opus 4.7 went through a major degradation a few weeks ago (way more hallucinations and rabbit holes than usual). Anthropic fixed it. Give it another shot.
I still find it lazy and confused vs 4.6. I don’t like adaptive reasoning.
Opus 4.7 seems very smart but the adaptive reasoning makes me always uncertain how hard it is actually trying. And it is far too argumentative. It seems to think it HAS to contradict you in ever response.
I have stuck with 4.6. I fully believe 4.7 can be smarter for truly complex and long running agentic use. But I prefer the more direct, literal mechanistic style and 4.6 seems to be peak Opus for that.
Stay with 4.6 if you can, it is disabled (afaik) on vscode claude code extension.
4.7 IMO is around 10-20% worse at understanding your prompt intention. You need more effort to explain your intention clearer so it doesn't divert.
Same. 4.7 intelligence is significantly worse than 4.6 on ALL 3P Harnesses. So only on Claude Code and Anthropic API/Subscription you get decent performance but on every other Harness and/or Cloud Provider inference (Bedrock) it performs worse than 4.6 on almost every task. This is not just anecdotal, i've talked to many colleagues from AWS, Microsoft and so on and they all agree that something fishy is going on.
I switched back to even Sonnet 4.6 in Claude Code over Opus 4.7. Every day or two I try a new task on Opus 4.7 and regret it.
Looking now I see that "Opus 4.6 Legacy" is an option that was not there before, so maybe Anthropic noticed that others are having the same difficulty.
Never used 4.7 outside CC extension VSCode. TIL, will keep that in mind
I was recently talking to someone about that! I wasn't sure if it was my imagination, but I felt like Opus 4.6 was way more diligent about looking things up online and making sure that its response was accurate. While Opus 4.7 seems content to just throw out an answer as quickly as possible with little care for accuracy; I started to always remind it to do an online search and to double check its work, to the point where I had to add a custom memory.
I switched back to 4.6 thinking, as most did, 4.7 introduced some jankinesss to it. I switched back soon enough to 4.7. I think I might've adapted myself to what and how 4.7 does things. 4.6 felt a step backward.
4.7 is better if your spec is clearer. 4.6 is better if you give it more freedom doing it's tasks. 4.6 felt it'll steer off often if you give detailed specs than 4.7 though, so perhaps that's it
Agreed. 4.7 is a smarter but weirder model. It will get confused in unexpected ways, but when it's not confused it will perform better than 4.6.
It's not a bad idea to skip it and wait until the next model release, but I personally will stick with 4.7.
How does their versionimg work? Because I've assumed that they're constantly tweaking their system prompts, I'm hoping in a couple of months, 4.7 will be improved over my first impressions- I caught significant hallucinations, something I'd rarely experienced with 4.6, if at all, I honestly can't remember one - but what I worried me was thebout the hallucinations I didn't catch.
That is a load-bearing decision!
That’s a decision-shaped comment.
I still use 4.6 if I need Opus. It's mostly GPT-5.5 for me. Only if I know it cannot do some thing like push without running the tests (because AGENTS.md said so), I switch to 4.6.
Although GPT's been acting weird since Thursday...
Switched back when 4.7 had an issue last week and it was wayyy faster. I assume mostly because a lot of people have moved off but might consider using it more just for the speed boost.
4.7 turned out to be a disaster in multilingual settings, so I sticked to 4.6 so far. 4.7 seemed to be optimized for (very specific slice of) coding at the expense of everything else.
It also seems to be designed to optimising the design / planning phase of a typical programming project.
I’ve stayed on 4.6. Was thinking of trying 4.7 though just today. Still, I did not jump on it day one.
I don't want to change from 4.6 because I'm finding it so good (I could change).
I've spent the last couple of days building Swift bindings to a monster CPP lib and I've actually had fun.
i use 4.6 and i've configured advisor to be on 4.7, so, when something's more complex the advisor can help. at least that's how i do with claude code, not sure of the others have implemented the concept of advisors.