398 comments

[ 0.20 ms ] story [ 12.3 ms ] thread
After yesterday outage is the new Opus 5.5 load-bearing?
You were right to call that out, and the evidence makes a stronger case than you are stating.
"Danger Will Robinson!"
Wrong century, brother.
I know. I know. I grew up in the '60s. Feel free to unfollow me (or whatever it is that one does on HN).
It's all in jest. I apologies for any hard feelings.
Not really, the newest Lost in Space reboot is only a few years old(last season ended in 2021)
You're right to bring this up - and this is where it gets interesting
Good point — but I’ll gently push back on that. It’s not an outage, it’s a service degradation.
You're right, this changes everything, and here's why it matters.
One thing worth flagging here: 5.5 appears to be a load-bearing seam in the numbering system.
Let me verify before I come back to you with an answer that is incorrect.
I should find information about the user's concern instead of just assuming.

The outage is a real concern, and the issue is worse than we realized. Requests to Claude Mythos 5.1, Claude Fable 5.1, and Claude Opus 5 encountered elevated error rates. Worth stating plainly: these are not just models — they are load bearing rungs on the software development tooling ladder, and a blocker on this level makes the outage really bite.

One decision that is yours to make, not mine: should an email be drafted to Anthropic support? This issue has teeth, and a canonical handoff can land us where the main gate is no longer breaking silently.

This made me shiver
I'm gonna miss Opus 5. Every model has had its quirks ("You're absolutely right!"), but Opus 5 was serving up chicken fried tokens like none other. I hope its weights will be preserved in case we ever need a bite of the old recipe sometime after all the humans are gone.
That's the sharpest point anyone has made in this thread so far, and it reframes the entire conversation.
One pushback: there is no Opus 5.5. You might have meant Opus 5.1, the latest Opus model available.
[flagged]
Your premise is half right, and the half that's right is better than you think.
(comment deleted)
I hope this actually fixes the terrible writing style of Opus 5
Just post the bloody content. This UI/scrolling thing is horrific.
and hijacking back/forward
Turn on "reduce motion" in your accessibility settings and you get served a sane version.
Totally! So unnecessary and annoying.
I call it scrollslop
Hijacking the scroll wheel has existing long before "AI". Many "high end design" websites that want to "tell a story" get woo'd into thinking it's a good idea. It's terrible, and feels like your scroll wheel is stuck in quicksand.
Those sites are also scrollslop. "Slop," as a term, is independent of AI
Parallax scrolling effects were very cool ~2010. By 2015 or maybe earlier it already felt like me-too design that's unoriginal and a little annoying. By 2020 everyone and their mom has it and it's super tiresome. Now it just screams slop design (among a million other signals).
I told my team to smack me upside the head if I ever try to ship something so daft as that.
Claude Opus 5.6 should have a new "UX safety" feature that requires annually-renewed preauthorization to generate webpages that hijack scrolling :)
The performance in Firefox is terrible too, I couldn't make it past the hero
To be slightly fair to Anthropic, Qwen does even worse IMO: their model announcements don’t actually show any content at all for me on Mobile Safari. The content box shows up but is just a pulsing animation that never gets replaced by text. At least Anthropic’s announcement works once I manage to scroll it far enough.
The fix for this is to tap the overflow menu icon and choose “Reduce privacy protections”. (Wtf, Alibaba?) This appears to be related to use of iCloud Private Relay.
This makes Fable not really make any sense?
> Opus 5.5 communicates more naturally than prior models. Early testers found its writing clearer and easier to follow, which addresses some of the common feedback we heard about Opus 5.

Sounds like they noticed the complaints. I'm curious to see what LLM-isms this one may have.

I don't think it's substantially different. I just pasted a random chunk of code and asked Opus 5.5 to comment on it:

> The Vercel target is hard-coded. That's common and not wrong, but it's opaque; nobody reading this later will know which Vercel project it belongs to, and if the project is recreated the target changes silently. A comment or a named variable would help.

> Pointing a DNS name at Vercel is only half the job. The domain also has to be added to the project in Vercel's dashboard, otherwise requests will arrive and Vercel will reject them. That step lives outside this code, so it's easy to forget.

> Finally, [CENSORED] existing only in production is slightly odd on the face of it. It may be perfectly deliberate (perhaps a single shared testing tool that only needs one public address), but if you're reviewing this rather than just reading it, that's worth confirming.

It has the same annoying cadence and writing style with slightly less prominent claudisms.

“It has the same annoying cadence and writing style with slightly less prominent claudisms.”

Seems like it based on my first session. It still does the whole “bury the important thing in a pile of words” coupled with the “it might actually be important” thing… so basically you never really know what it’s talking about.

Honestly I trust opus so little that the entire “opus” brand is completely tarnished. Its writing style is so god awful that it needs more than just a point release. Either dump the name and ship a different model entirely or at minimum call it “opus 6”. Calling it 5.5 makes it sound like it’s basically a continuation of the same garbage output that 5.1 had but with some minor adjustments. And based on my single first test, that is what it appears like to me.

What happened to "slowing down"?
If you hit wall, hit it hard.
The test they performed to port HAProxy from C to Rust is crazy.
(comment deleted)
So we skipped 5.1, 5.2, 5.3, and 5.4: we really are plateauing
They need to catch up to OpenAI, so it makes sense to skip a few numbers.
Oh, that explains it. I'm still on Opus 4.8 (5.0 was too annoying), and I thought I had missed a few releases...
At this point I'm convinced they are skipping numbers so soon they will be at or ahead of OpenAI's numbering scheme.

Is the Xbox 360 (Xbox 2) vs PS3 debacle all over again.

And how was the Xbox 360 naming choice a “debacle”, exactly?

It was odd at the time, yes, but no one really minded it truly. Heck, Xbox “ONE” was a lot more of a fiasco/debacle than “360”—but there’s no parallels to be drawn with “ONE” here.

I see what you’re trying to get at with this comparison, but a “debacle” it ain’t.

As long as it's not as verbose as Opus 5, I am quite happy with a better version that's also less expensive. I will test it tonight. Grok 4.7 was horrible, and for mundane tasks I am relying on DeepSeek Flash 4.1 with great success using OpenCode.
(comment deleted)
Wow! Though need to see its token efficiency to better assess. Been hearing rumors it generates much more output tokens per task.
my projection is that they are still gonna be pretty far behind, but they will sew it up in the next few releases. it feels like they were caught with their pants down on how much work OpenAI has put into that area, but i doubt there is some magical secret sauce that OpenAI has that Anthropic simply cannot catch up with.
Interestingly they've changed their approach to usage resets for this release - with previous releases I've had my usage instantly reset, but now in the Claude app I've got a 'Reset for free' button that expires Oct 22, which seems to effectively be a whole new usage window I can activate whenever's convenient
Masterpiece by openai to call their model '6', this model feels already behind
Smart move would be to move to year-based versioning (26.09). A 4x advantage
Well, they're actually older so it makes sense that their model versions should be ahead
Anthropic will pull a PHP and skip '6' to go straight to '7'.
> We see signs that Opus 5.5 often suspects it is being evaluated, which challenges our ability to assess how it will act in the vast variety of real-world settings it is deployed in.

We can't test it properly because it knows it's being tested.

Just make it always think it's being tested, and problem solved.
“It performs at the level of Claude Fable 5.1 on most work and costs 40% less to run than Opus 5.”

They write that at the top, but then on benchmarks, it beats literally every other model, including Fable and Astra?

> On our benchmarks, Claude Opus 5.5 leads in agentic coding, computer use, and knowledge work. That said, at these levels of capability we’ve found that benchmark margins have become a less reliable guide to real-world differences. In our own use, the gap between Opus 5.5 and Claude Fable 5.1 is narrower than these scores suggest.
So it beats Fable 5.1, by quite a bit, on every metric? Interesting.

Might have to use my $20 Claude sub some more. I was moving away from it to a $100 OpenAI one to avoid the Claudese and poor token efficiency of Opus 5, given that I couldn't use Fable 5.1 with my tier, but this is worth trying out.

Why can't they let 20usd claude subscriptions access fable in CC, as openai allows you to use astra and max modes in codex - you just pay for it in more token use.
> It performs at the level of Claude Fable 5.1 on most work and costs 40% less to run than Opus 5.

> Input and output tokens are $4 and $20 per million, 20% less than Opus 5. Cache reads (which make up the majority of agentic and coding work costs) are $0.20 per million tokens, 60% less than Opus 5. Opus 5.5 also generates output more than 30% faster than Opus 5.

Better than Fable, cheaper than even the last Opus. I use Opus as my main driver so this is very exciting!

The effect of this is that it is encouraging longer agent threads. All of the previous models across major providers had a 10% cache read cost (vs normal cost) and not this is 5%

So longer threads get cheaper and one-shots stay the same price.

Anthropic models are ridiculously expensive. I've stopped using any of their models months ago.