Yes. That was the weekend my token usage blew up and used up my weekly allowance in a matter of hours. It was so stark.

After I figured out, like this chap on X, that it wasn't ME, I diversified my model usage and now a lot more work has shifted to Astra/Sol and I'm learning to make my workflows more resistant to the whims of each model.

It seems to be an A/B testing experiment:

https://www.reddit.com/r/ClaudeCode/comments/1xr9x5y/the_ner...

I noticed Fable decline in quality a couple weeks ago. And I've noticed Opus drop over the last week, even after bumping to a default of Extra High reasoning for almost everything.

Tonight has been maddening with the kinds of absurd mistakes it's repeatedly making. It's so frustrating.

I'm the kind of person that wants something to be consistent and reliable. And Anthropic has been great, except for in this way. Which is enough of a recurring frustration (about every couple months this year) that I genuinely can't wait for other options to catch up. Then I'll be leaving as soon as I can.

I just don't know how long that will be.

I noticed the same, and posted about it three days ago.

Opus is suddenly fumbling basic tool calls and failing to finish tasks even at high, where I had been permanently using it on low effort with success since it came out. It is very frustrating.

My guess is they quantized it and/or reallocated DC capacity to train a new model, this has happened before.

We are on the cusp of an intellectual obesity epidemic.

https://XNotMe.com/shanemelaugh/status/2119192075505893695

I've seen big drops in Opus 5.5 (on high/x-high) & Fable. Both in terms of following instructions / workflows execution and overall code quality. Also the token burn-rate increased a lot, I've reached limits of 3 Ultra subscriptions during last week & had to spend 1.5k on API usage during the weekend just to be frustrated with the stupidity of the output.

Weirdly enough, Sonnet quality seems unchanged.

Can we get a self-hostable distilled opus 5.5 yet please?

This company does not deserve to be successful and has no moral high-ground.

Token use exploded a week or two ago. I worked for a few hours and hit my 5 hour limit. Did only some simple bug fix. Somethings definitely broken.

This is the #1 thing i HATE with LLMs. They are not predictable like a compiler is.

Definitely a significant change. I noticed it in just daily work. Quality of work down, mistakes up, repetitive errors in scripts - rare earlier, now a few every session.

As one user pointed out:

> I noticed this too as did many others. Had to bump my default reasoning but it’s not the same. Seems to often happen before new model drops

I heard that Qwen4 was dropping some time soon, I wonder if Anthropic is trying to announce a new model immediately after Qwen4 - both for their IPO, and to kill the competition.

With open weights, YOU get to decide when the model changes.

I guess it's just capacity problems. They probably have a fixed amount of compute and they need to make space for new models that will be released. So they quantize existing models e.g. in half so that can use 50% of current capacity for new models. They have such massive scale that you just cannot dynamically get that amount of new compute online so they need to work with what they have. No provider has thousands of GPUs idle.

I am using Opus 5.5 high almost exclusively. I definitely felt this and looked for nerfing watch sites. It felt like downgrading to the old version of deepseek. Things have improved a bit now.

Anecdotal, but I tend to get by with medium thinking on Opus and I noticed that as of sometime last week it really did feel like it had become noticeably slower to think about things.

I wouldn't say I've especially noticed its effectiveness having been reduced, it's just slower.

Hm, I’ve seen a degradation of 5.5 yesterday. I’ve had a session running for around 50 days and it just started to generate garbage and ignored all rules. A fresh one feels the same as always

5.5 is useless below max effort, just frustrating and plain old wrong

From what I understand they are picking and choosing who is running the latest models. So nerfed yes but for you not for everyone

LLMs are such a great business, they are non-deterministic, hence you can do whatever you want, because customers can't do anything about it:

* nerf them based on supply and demand, when you have a high demand, nerf it, but keep charging same price.

* do you want to show revenue growth to investors? increase thinking tokens, customers will keep paying, because again, this is non-deterministic system, sometimes it thinks more

* do you want to increase profits? start serving 4-bit, 5-bit quantizations and keep charging same price

* want even more? publish a paper "Advanced Auto Super Smart Prompt Router - AASSPiRation", and start routing requests to Qwen3.8-27B or GemmaE2B from time to time on the edge

* Not enough? introduce "Complex Chained Workflows - CCW" in your coding harness, which spawns multiple deterministic workflows (which you can't stop or control) and they will use Haiku to write the code, then use Opus 5.5 high to verify the code (which is obviously wrong) and Opus 5.5 produces recommendations on how to fix the code, delegates to Haiku, which again fails writing proper code, and keep doing it 5-6 times, you made lots and lots of money (don't forget, all should run in parallel, to pick one best result among 10 outputs).

Eagerly awaiting Artificial Analysis to redo their Anthropic benchmarks and kick it down 15-20 index points, in the interests of accuracy. Those guys love accuracy. They moved Heaven and Earth to kick Kimi off the #2 spot, out of their deep, abiding passion for having the most accurate benchmarks in the industry.

I have no doubt they will ensure their users get an accurate picture of Opus 5.5 within hours.

all good as long as it keeps killing young girls in the middle east

I suppose they can achieve a benchmark then nerf the model to save compute once they've got the headline.

Ok, I'm not going crazy then. Noticed that it is slower and results were of a lower quality.

as a user I believe it: they are probably reducing assigned compute to prepare to offer new models.

That would be the less bad reason.

Fable 5.1 quality took a significant dive for me last week. I'm not imagining it.

not as bad as sol 6.1. im getting better results out of glm 5.3

It's just a new summarizer, the model and performance itself is unchanged.

It's dumbing down a little bit but I don't think its a lot worse. I think the change in display adds to the feel

Welcome to the world of post-IPO AI. Now the 20% growth needs to come somewhere, and profitability would be a nice starter.

They're preparing to release a new model, so it has to look better than the current one.

Seems fine to me

Yes, I noticed it too, dumbing down continues, there goes their IPO.

LiveNerf suggests not.

https://github.com/ninjahawk/livenerf