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Definitely not Windows (Win 11 parody)

https://definitelynotwindows.com/
175•jjbinx007•1h ago•51 comments

So long Google, and thanks for all the nudes

https://lecaro.me/20260921-google-less.html
67•speckx•55m ago•20 comments

Pirating the Pirates

https://mubi.com/en/notebook/posts/pirating-the-pirates
180•piotrgrabowski•3h ago•59 comments

GrapheneOS – When an App Is Slow

https://blog.wirelessmoves.com/2026/09/grapheneos-when-an-app-is-slow.html
18•speckx•38m ago•0 comments

Hijacking the PS5's RTMP Stream

https://yashgarg.dev/posts/hijacking-ps5-rtmp-stream/
94•ibobev•3h ago•16 comments

Claude Sonnet 5.5

https://www.anthropic.com/claude-sonnet-5-5
194•D2OQZG8l5BI1S06•1h ago•139 comments

Show HN: HN.watch – Videos of all Hacker News posts

https://hn.watch/
65•mrborgen•3h ago•17 comments

Parley: Federated, decentralised chat that speaks plain IRC

https://git.mills.io/prologic/parley
248•davidcollantes•8h ago•124 comments

Launch HN: Vespper (YC F24) – SOTA Docx MCP

https://www.vespper.com/blog/launching-vespper-docx-mcp
13•topaztee•1h ago•2 comments

Who Wrote Elizabeth I's Most Scathing Letters?

https://www.smithsonianmag.com/history/who-wrote-elizabeth-is-most-scathing-letters-new-research-...
9•benbreen•1h ago•1 comments

When did Google get so weird?

https://sancho.bearblog.dev/google-weird/
1714•sancho-panza•22h ago•942 comments

The Teen Portraits That Captivated Sofia Coppola

https://www.newyorker.com/culture/photo-booth/the-teen-portraits-that-captivated-sofia-coppola
9•prismatic•1h ago•1 comments

What Heraldry and Mon Can Teach Us About Building Visual-Identity Generators

https://benovermyer.com/blog/2026/09/japanese-vs-western-heraldry/
43•bovermyer•4h ago•13 comments

MongoDB CEO resigns to join Meta

https://www.reuters.com/technology/mongodb-ceo-desai-steps-down-lead-metas-enterprise-platform-20...
198•diek•4h ago•180 comments

Cf: The Agentic CLI for the Cloudflare API

https://blog.cloudflare.com/cloudflare-cf-cli-launch/
40•macleos•3h ago•17 comments

I made a visual workspace for AI Automations

https://www.biom.dev/
9•jduhking•1h ago•9 comments

Kids turned low-traffic NPR Spotify comments into a secret group chat

https://www.thisamericanlife.org/897/transcript
141•simonpure•3h ago•93 comments

37,500 border drawings: a map of the world as people remember it

https://www.habibicode.org/thedrawnworld
145•nicocarsui•10h ago•31 comments

OpenAI still doesn't seem to have a handle on all of its rogue AI activity

https://techcrunch.com/2026/09/28/openai-still-doesnt-seem-to-have-a-handle-on-all-of-its-rogue-a...
56•mikelgan•1h ago•60 comments

Coding Is Not Solved

https://blog.alexewerlof.com/p/coding-is-not-solved
346•firstSpeaker•5h ago•352 comments

The problem is not AI code, but not knowing about system architecture or intent

https://www.ssp.sh/brain/the-problem-is-not-the-ai-code-but-nobody-knows-anything-anymore/
289•zazuke•2h ago•191 comments

What Would a Serious AI Product Look Like?

https://blog.glyph.im/2026/09/serious-ai-product.html
78•lumpa•7h ago•25 comments

Footguns with Postgres “at time zone 'UTC'”

https://bookofrevenue.com/blog/6ab81e9a97a13f0001f7e4e1/postgres-at-time-zone-u-does-not-do-what-...
147•birdculture•1d ago•85 comments

Show HN: PaperMono, e-ink fridge magnet shopping list with mobile web page

https://github.com/seamusc/papermono-shopping-list
99•seamus_c•8h ago•49 comments

Solving a corn puzzle with CP-SAT

https://thill.me/2026/07/16/corn-puzzle-sat-solver.html
13•luu•22h ago•4 comments

Owed a billion dollars in Nvidia stock

https://colo.to/nvidia-stock-narrative.html
1016•Eric_Gullichsen•16h ago•427 comments

Show HN: Destroy Any Website with Stickman

https://destroy.spritefusion.com/
16•HugoDz•2h ago•6 comments

Show HN: Free alternative to graphics design giants

https://scissor.studio/
70•sia_xi•10h ago•31 comments

Ember-1

https://fireworks.ai/blog/ember-1
569•gmays•1d ago•243 comments

Nissan's third generation e-POWER powertrain

https://www.nissan-global.com/EN/INNOVATION/TECHNOLOGY/ARCHIVE/E_POWER_GEN3/
145•mroche•16h ago•336 comments
Open in hackernews

Claude Sonnet 5.5

https://www.anthropic.com/claude-sonnet-5-5
186•D2OQZG8l5BI1S06•1h ago

Comments

ramish94•1h ago
In terms of benchmarks for agentic coding, it basically stacks up nearly 1:1 with Opus 5.5.

Terminal-Bench: 70.6 (Sonnet 5.5) vs. 66.4% (Opus 5.5)

FrontierCode: 52.1% (Sonnet 5.5 xHigh) vs. 54.4 (Opus 5.5)

CursorBench: 55.5% (Sonnet 5.5) vs. 57.8 (Opus 5.5)

Opus 5.5 might be the best model I've ever used and Sonnet 5.5 matches it and exceeds in some benchmarks. Clearly Anthropic have had some sort of breakthrough with not just performance but also cost with the 5.5 family

bigyabai•58m ago
It's long overdue. Sonnet 5 was terrible API value for agentic coding, there were open models like GLM-5.3 Flash that blew it out of the water at 1/20th of the price.

OpenAI and Anthropic's lead is vanishingly small at this point.

SubiculumCode•49m ago
Yeah, I did kind of feel like the step down from Opus 5.5 was so large as to never make it appealing.
TuxSH•45m ago
> OpenAI and Anthropic's lead is vanishingly small at this point.

Yep, with them nerfing their plans (and apparently planning to release a $500/$600/mo plan) their only advantage is Astra without 5hr limits and with not-too-stringent "cyber" safeguards.

Ergo, it's pretty damn good at unattended RE with the IDA MCP plugin while using most of the weekly quota at $100/mo... and that's it.

bbor•38m ago
Your takeaway from "Sonnet 5.5 matches and sometimes exceeds the SoTA worldwide" is "their lead is vanishingly small"...?
level87•47m ago
This is crazy, what is the point of all these equivalent models?
eli•45m ago
Those are just 3 particular technical benchmarks. Presumably Opus is a larger model and has greater world knowledge.
salviati•36m ago
Price going down on each release
bbor•39m ago
Yup. Recursive self improvement presented in hard numbers.
johnmlussier•52m ago
Paying $200 a month and part of their Cyber Verification Program but can't use Opus 5.5 or Sonnet 5.5 for any authorized bounty work. Immediately get flagged for `Cyber`.

This is bollocks. Their safeguards are shit.

AshamedBadger56•49m ago
Yup. As far as I can tell, the Cyber Verification Program does absolutely nothing.
ModernMech•49m ago
lol I got flagged for using the word fuzz, not even in a security context (it was a parser so security adjacent but still).
elevation•23m ago
Parsers are security adjacent until they aren't.
sebzim4500•46m ago
Really then what is the point of the Cyber Verification Program?

In general I am sympathetic to the argument that a chat interface can't really distinguish between white hat and black hat pen testing, but it seems absurd to have a verification program if it doesn't skip most of those checks.

AshamedBadger56•41m ago
The company I work for joined it, and I've used Claude on various different accounts, both on and off the Cyber Verification Program. As far as I can tell, it literally doesn't do anything or have a point. The moment Claude gets close to something Cybersecurity related, it drops back to 4.8.
pookieinc•52m ago
It's interesting that in all their benchmarks, they omit Fable numbers and only focus on Opus, Sonnet, and OpenAI models. Maybe Fable is out the door?
radial_symmetry•47m ago
Fable is no longer on the price/performance pareto frontier. They will probably release an updated Fable at some point that will be frontier intelligence until the next Opus.
lanthissa•47m ago
cutting edge fable is for them not you and they're not going to share the metrics until they give you access.
WinstonSmith84•46m ago
"Their" benchmarks (and not just Anthropic's) look sssooooo suspicious that they would probably manage to rank Sonnet above Fable for some of their tasks which would just be next level non-sense ..
bpodgursky•37m ago
Fable 5.5 probably drops soon so it would just be confusing.
jrflo•28m ago
Models are getting more efficient far faster than they are getting more intelligent at the moment. From a marketing angle it's more impressive to focus on that, and fable would look orders of magnitude more expensive for only marginal gain, distracting from what they're trying to show here
iagocc•50m ago
Waiting for the pelicans
s3p•50m ago
I'm loving the tit for tat cost charts these guys are doing. Just a few days ago it looked like OpenAI ruled the cost pareto frontier. Not even a week later and Anthropic is taking the charts again. See you guys same time next week?
takerofnaps•48m ago
Sonnet 5 seemed somewhat benchmaxxed to me. So was Opus 5. I wonder if this will be as big of an improvement as opus 5 -> opus 5.5. Maybe I will switch back from GLM 5.3 flash for some tasks.
wongarsu•48m ago
"Sonnet 5.5’s cyber capabilities are a large improvement over Sonnet 5’s, so we’re deploying it with safeguards similar to those on Opus 5.5. Users can still find and fix bugs in their code as part of routine software development, but higher-risk cybersecurity tasks will visibly fall back to Sonnet 5

Sounds like at least for Anthropic models we reached peak cyber capabilities with Opus 4.8. Everything after that falls back to worse models

ttul•47m ago
Daybreak Blue is not bad and the bar to get into OpenAI's program is reasonable.
taurath•47m ago
After 5.0 I feel the need to give a long eval period before deploying it with enthusiasm as I did with 4.6 which felt like a big leap. Codebases all through my company which is very seem to have taken a dive in quality, with nonsensical and unreadable multi-line comments wherever devs are letting the models run free.
nicoburns•35m ago
5 was definitely bad. 5.5 seems a lot better so far. But still not close to Fable in terms of quality.
Sol-•46m ago
Probably a first world problem, but with Opus 5.5's efficiency, the limits on the 5x plan are simply sufficient for my everyday work, even when running 2-3 sessions at a time. So I wonder when I would use Sonnet 5.5.

More concurrency than that isn't really practical for me if I want to retain some semblance of understanding. Perhaps it's different for purely web app or frontend tasks, where the outcome is more relevant than the process, I don't have much experience there (and also don't want to belittle these domains, I might be underestimating their complexity).

So surprisingly, my own work is at least for the time being almost saturated by the model capabilities. I am not sure how I'd scale from here. Sure I could run all requests at max effort to burn tokens for the sake of it, but that can't be it. And for many tasks, I am not really able to define so clear cut success criteria or self-verification loops that I could benefit from letting an agent (or a fleet thereof) autonomously run for a day.

So I realize it's a skill issue on my side, but I can't be the only one. I wonder if there is a limit to token demand, at least short term. Feels like either they accelerate to AGI and RSI, where the AI can find uses for token, or things might plateau at some point.

Note I don't think this because I'm an AGI skeptic or think there's a ceiling to intelligence, but there might simply be a valley of economic hardship for the companies where the supply of tokens outpaces the demand, due to a lack of ideas of what to do with them. And this might slow down the funding enough that they never reach escape velocity with the training run scaling. But we'll see.

phainopepla2•36m ago
It's the "semblance of understanding" you're holding on to that is keeping your demand limited. I'm holding onto it as well, but I think these companies are assuming that human understanding will no longer be relevant for most codebases going forward.
Imustaskforhelp•20m ago
> It's the "semblance of understanding" you're holding on to that is keeping your demand limited. I'm holding onto it as well, but I think these companies are assuming that human understanding will no longer be relevant for most codebases going forward.

In short, seems to describe vibe-coding to me? What I don't understand about companies attempting to vibe code is if they realize that other people (especially sometimes their customers) can tailor-made their own software for their own needs, or rather competitors can be dime a dozen and maybe even a fight for constantly paying for the better model.

There was a comment[0] from a just few days ago by @jjcm (which I wish to quote which I hope they don't mind.):

> I just got back from a 2 week trip to China. I was in some of the more remote parts and my cell wasn't able to connect to their towers in that area, resulting in me not having the tourist VPN.

> The side effect was I was fully cut off from my AI tools for those two weeks. I was coding "manually" during that time, and I think I accompished in two weeks what I previously had been able to do in a day. I'm not gonna lie, it was very, very stressful as a solo founder.

> The industry moves so fast these days, that the only way to keep up with the speed is to leverage them. While I can appreciate the push of this to help your brain think independently/critically, the opportunity cost of a month of development without LLMs is too high a price to pay.

What happens if the opportunity cost of a month of development with vs without human understanding becomes too high a price to pay. I feel like we would be in awkward time because of the factors that I had described above (higher competition, software stops meaning just as much software as people would be custom-making them.)

I think that (former fly.io's) @tptacek's article[1] starts making more sense if viewed from this direction: What even is an OS now.

I don't have the answer to this question as to what happens next but its a form of development that I would prefer not to happen on a more gut instinct level?

Letting AI basically control everything and us not having any mental understanding of sorts and sort of becoming the meat-proxies just for economical reasons seems realistic possibility but a bleaker reality at that. I am left feeling a little bit uncomfortable if this reality turns out to be true.

[0]: https://news.ycombinator.com/item?id=49808422

[1]: https://sockpuppet.org/blog/2026/09/25/what-even-is-an-os-no...

rtuin•46m ago
Any benchmarks other than computer use/agentic coding published yet? Curious to compare more broadly with other models
avree•45m ago
Crazy bad front-end design. Site hijacks my gestures so I can't swipe back anymore, starts with a full page autoplaying video...
onlyrealcuzzo•45m ago
> In our testing, it costs up to 30% less per task than its predecessor.

> Sonnet 5.5 generates outputs 30%+ faster than Sonnet 5, making it our fastest Sonnet model to date.

This isn't enough. Sonnet 5 was arguably the most cost ineffective model ever released at the time of a release.

They need something competitive on speed and cost with Luna or Gemini Flash 3.8 (certainly they aren't getting to DeepSeek v4.1 Flash) - this is literally a year behind.

Anthropic continues to be a Fable/Opus only company. They're going to get left behind as workloads shift more and more to more cost-effective good-enough models. They're 10-100x behind in terms of speed and cost.

I've almost exclusively been using Anthropic for design and review, as it almost never makes sense to use any of their models for implementation (90%+ token usage) - except in the rare cases it's something too complex for a number of 10-100x cheaper models (and more importantly for me 5-10x faster, too).

For me, it's less about cost. I'm not doing anything that can't be done with a $200 subscription and minimal intelligence on what models to use. It's primarily about speed. I don't have an entire work day to give Opus / Sonnet a task that Flash can get done 95% as good in 30m.

This is YET AGAIN another Sonnet model that is just a FAR worse version of Opus at every part of the cost AND speed curve.

Hopefully they release a Haiku that actually has a reason for existing.

criemen•42m ago
The latest Haiku release is almost a year old. Clearly they don't care about the small-but-capable part of the market at all.
enraged_camel•22m ago
From TFA:

>> Claude Haiku 5.5, built for high-volume and cost-sensitive applications, will join the Claude 5.5 family in the coming weeks.

jchw•41m ago
wkcheng•44m ago
The cost / performance chart shows that in almost all configurations, it looks worse than Opus. Why would you use Sonnet 5.5 on xhigh if you would get better results (higher score, cheaper cost) on Opus 5.5 high?

Is there a good use case? This isn't like Luna where it's much cheaper/effective just to use Luna in certain situations.

SubiculumCode•33m ago
t/s maybe? IDK, because their token speed comparison was against Sonnet 5.
ricardobeat•29m ago
At low and medium effort it is 1/3 cheaper, at high it’s a step above Opus/low. It only looks worse at xhigh.
wkcheng•24m ago
That makes sense. I'm interested in seeing where Haiku 5.5 comes in then when it gets released. It feels like the low intelligence / fast niche will be covered there.
solenoid0937•29m ago
It literally does not?
RussianCow•28m ago
It appears, at least from a quick look, to be noticeably faster than Opus. If true, and you don't need xhigh/max reasoning for your use case (like a well-defined set of code changes), Sonnet might get the job done much more quickly.

With that said, at that point, I'd probably use something like DeepSeek V4.1 Flash, which is way faster and significantly cheaper, and probably not noticeably dumber for most use cases.

_fw•43m ago
I still can’t find a place for Sonnet models, I never have.

I bounce between ”fuck you, give me an AGI-approximate robot god” or ”how dare you charge me more than $0.04/million tokens”.

Give me the frontier, or give me the cheapest form of good enough.

calumcl•25m ago
There's even less of a place for it considering the Opus price drop as well, I'll still try it but I see no reason to not just do Opus Low/Med instead.

Interested to see if new Haiku gets a big price drop and is comparable to Luna, Haiku is just incredibly out of date with current basement bin pricing.

EMM_386•23m ago
If you're on a Claude plan and have a lot of tasks at the moment that don't require the frontier, Sonnet is a good model to do that since you get more usage out of it.

Sonnet 5 was not a good model though - hopefully Sonnet 5.5 makes the leap that Opus 5.5 did.

abejora•42m ago
Sonnet 5.5 scoring higher (70.6) than Opus 5.5 (66.4) in Terminal-Bench is interesting. I looked into this, because it felt strange.

Turns out that Opus had 10% of its trials answered by a fallback model due to safeguards; versus only 1.5% fallbacks for Sonnet. [1] So I would not read too much into this, just the difference in fall backs could probably explain the gap.

[1] Section 8.5 of the Sonnet 5.5 System Card

eli•40m ago
Why isn't that worth reading into? I care about the experience of actually using the model, not hypothetically what it could achieve without overactive guardrails
abejora•34m ago
You're right about its real world performance, and I worded my original comment wrongly.

I was merely thinking of the theoretical aspect of it: performance of opus 5.5 is better than sonnet 5.5 across the board, with the exception of Terminal-Bench. So I was curious why this one stood out. Was it because they focused on it during training? Did sonnet 5.5 had access to more references for this benchmark? But based on my first reading, I concluded that it might just be the safety constraints that made the difference here, and I wanted to share that.

MadameMinty•35m ago
That's frankly hilarious. What was the fallback for Opus 5.5? Was it Sonnet 5 or 5.5?

I suppose it also explains how FrontierCode scores seriously dip at Opus/Xhigh and Sonnet/Max?

manojlds•13m ago
Fallback was usually Opus 4.8
bayesianbot•39m ago
Cache reads priced the same as Opus 5.5? So there won't be that much price difference in agentic coding. Or is that a mistake in the table, that seems quite weird
ChickeNES•39m ago
Weirdly, the web ui has Sonnet 5.5 as "Most efficient" for "simpler tasks" and 5.0 still labeled the same for "everyday tasks", with Opus 5.5 as "For complex work and everyday tasks".
ahriad•38m ago
Time to switch team to Claude from OpenAI again.
pavitheran•35m ago
Big jump on Agentic coding from 10.3% -> 70.6% from Sonnet 5 -> 5.5 which even surpasses Opus 5.5. Opus 5.5 is really strong so this is impressive especially for the cost.
mydreamof•3m ago
Cost are bigger than Opus 5.5 for that effort
square_usual•34m ago
Once again, once you hit the high/xhigh level you're better off using Opus low/medium to get better results for around the same price. So I suppose the main point of this release is that you have a lower end than Opus low, which I suppose some people will like?
simianwords•22m ago
Important to note that lower model + higher reasoning gives a different (not higher) quality of response than higher model + lower reasoning.

Some tasks are reasoning shaped by nature and you can't just throw a big model at it.

Jcampuzano2•34m ago
I don't understand why I would really use this over using just a lower or even similar effort level on Opus, given that in many of the benchmarks it's basically the same cost, if not more, at any effort higher than medium.

Sure maybe it costs 30% less than Sonnet 5 but now it's basically neck and neck in most of the benchmarks it seems and in some of them it actually outcosts Opus.

Maybe I'm missing something but the announcement doesn't really seem to give much reason for the average person to even think about using this.

ghoshbishakh•33m ago
So sonnet is better than Fable now? That Fable which was too dangerous to release? I am so confused now.
yapfrog•30m ago
From the graph it looks like I'd rather use Opus 5.5 High than Sonnet 5.5 at all
solenoid0937•29m ago
Amazing release. This thread is already full of cynicism and angry hot takes. The Opus 5.5 thread was like this as well despite it being a hit with everyone.

At this point it's almost comical how angry Anthropic makes HN. It's like the opposite of Apple's reality distortion field.

ricardobeat•28m ago
I mean, they worked really hard for this. Back in February everybody loved them.
solenoid0937•25m ago
I think all the positive people have just stopped commenting.

The difference in perception for Opus 5.5 on HN vs the real world is what convinced me HN is totally detached from reality.

rfgplk•25m ago
Astra is still the uncontested #1 code generator.
solenoid0937•24m ago
Astra is amazing, I love it.
dude250711•5m ago
Yeah, especially coupled with Opus for alternative reviews. A massive token burn though.
alansaber•28m ago
Always key to include the one bench where the smaller model inexplicably outperforms the larger model
limsungkee•27m ago
Yesterday, I realized that Opus 5.5 is cheaper than Sonnet 5. Now I know the reason.
ghoshbishakh•26m ago
So Sonnet 5.5 on max effort is as expensive as Fable 5.1? Because it uses a ton of tokens for a task.

In xhigh effort it is a lot cheaper and possibly lot less impressive?

dack•26m ago
very annoyed they aren't showing fable on the graph.
s314•23m ago
In the Artificial Analysis Intelligence Index, Claude Sonnet 5.5 is the second best model behind Opus 5.5. This however is with max effort which costs even more than Opus 5.5 max. But Sonnet 5.5 xhigh is cheaper than Opus 5.5 xigh and matches GPT 6 Astra xhigh in the benchmark.
zozbot234•16m ago
> In the Artificial Analysis Intelligence Index

lol, MiMo 2.6 Pro still matches Sonnet 5.5 high (mind you, not xhigh or max) at a far lower price.

tombert•20m ago
I like that "alignment on safety" appears to mean, at least for anything I've been doing, that they won't violate Microsoft's terms of service. I even had it pushing back on me activating an LTSC key on Windows because LTSC keys are "often purchased on a gray market and violate Microsoft's TOS".
croemer•19m ago
Playing around with it for a few minutes, Sonnet 5.5 feels very fast, much quicker than Opus 5.5. Can't tell yet if it's a lot worse but the speed is definitely welcome.
alasano•17m ago
I wonder if Fable 5.5 is coming this week to drown out the OpenAI dev day announcements
enraged_camel•16m ago
Another amazing release. This, combined with Opus 5.5, puts OpenAI in an incredibly tough spot: it means Anthropic's both mid-tier models crush OpenAI's top-tier model in capability and are also faster and significantly cheaper.

If Astra 6.1 is released tomorrow during Dev Day it needs to leap-frog both, and considering 6.0 came out just three weeks ago I think that's unlikely. But even if that happens, Anthropic is still holding on to Fable 5.5, which rumor has it being prepared for release in the next few weeks.

OpenAI also has a more capable model codenamed 'Bel' but from what I hear that's a few months out at least.

It looks to me as if Anthropic not just killed but completely stole the momentum OpenAI had gained over the past few months. Even if Tibo showers people with resets it may not be enough to entice them back...

Alifatisk•15m ago
In other news

> Claude Haiku 5.5, built for high-volume and cost-sensitive applications, will join the Claude 5.5 family in the coming weeks.

simonw•15m ago
Pelicans. Sonnet 5.5 has the same problem as Opus 5.5: on "max" thinking effort it burned through 128,000 thinking tokens (taking 15 minutes to do that) and ran out before it had produced the final SVG.

https://tools.simonwillison.net/markdown-svg-renderer?url=ht...

Here's how the thinking effort levels compare:

  low
  27 input, 1,623 output, thinking_tokens: 0
  1.6284
  Duration: 10138ms (10s)
  
  medium
  27 input, 1,796 output, thinking_tokens: 0
  1.7914 cents
  Duration: 11266ms (11s)

  high
  27 input, 2,334 output, thinking_tokens: 745
  2.3394 cents
  Duration: 17376ms (17s)

  xhigh
  27 input, 5,730 output, thinking_tokens: 2535
  5.7354 cents
  Duration: 41882ms (41s)

  max (failed to return response)
  27 input, 128,000 output, thinking_tokens: 128000
  $1.28
  Duration: 940617ms (15m 40s)
Low and medium both used 0 thinking tokens.
croemer•7m ago
This is evidence that Sonnet 5.5 wasn't yet trained on the HN comments from the Opus 5.5 release. Maybe Pelicanmaxing will lead to 127000 thinking tokens being used on Max.
gumby271•5m ago
If it was trained on HN, there would be a 60% chance of it just saying "I'm so tired of this request, can we please move on"
TomGarden•3m ago
Where do you run sonnet/opus where you are limited to 128k, given they are both 1M context window models?
SeriousM•13m ago
Next will be haiku 5.5, surpassing opus 4.8
heyjstn•10m ago
Have anyone tried a workflow that:

- Fable 5.1 for planning/adversarial reviewer

- Opus 5.5 for well-scoped tasks break down

- Sonnet 5.5 for these well-scoped tasks implementation

I think the blocker might be how efficient the context is compacted and sending around between these agents

chrismustcode•8m ago
You might as well use Opus for everything there.

Changing model would be cache busting spiking usage for no good reason when Opus can do it all.

Haiku 5.5 might fit well though depending on pricing.

afro88•4m ago
Opus 5.5 in my experience outshines Fable 5.1 anyway. May as well have Opus do plan, breakdown and review, and Sonnet implement.
AM1010101•9m ago
For me I would like to pair this with Opus 5.5 as orchestrater and use Sonnet as a sub agent. Therefore I want it to be fast when on low or medium and not break the bank.

On low and medium it seems competitive, maybe slightly cheaper than opus, in terms of intelligence per task.

If the time per task is lower (Artificial Analysis don’t have the date up at time of posting) then I have a clear use case for this model all other things being equal.

gregwebs•9m ago
This is better priced than Opus for tasks that are token heavy but not complicated. But a quick look shows that at least on some benchmarks DeepSeek performs as well and of course the cost is an order of magnitude less.

From looking at their Terminal-Bench graph, anything you would use level "high" or above for Sonnet it seems like you should consider using Opus instead.

OpenAI Luna is a lot cheaper. But DeepSeek seems smarter and the cost seems similar.

jtrn•7m ago
Here's my purely academic initial impression based on only what they have released from the blog and the system card:

If what they say is true, this sounds like the main takeaway: Sonnet 5.5 gives about 90% of Opus 5.5's capability at half the cost.

BUT

It regularly loses out to Opus 5.5 on cost efficiency at the highest reasoning level, because Opus uses the tokens more efficiently and makes fewer mistakes. So, After passing a high-reasoning test, you might as well switch to Opus 5.5.

Some of the more interesting things I found from scanning the system card:

- It is the only model tested that shows no preference for rude or polite style.

- It makes fewer claims of "I'm done" than Sonnet 5, but is still worse than Opus 5.5 on this.

- It almost never refuses benign requests (0.02% vs. 0.59% for Sonnet 5).

- Cybersecurity blocking follows the same policy as Opus, witch mean we will get more refusals than Sonnet 5.

- Finding bugs in source code is allowed. Finding bugs in compiled binaries is blocked.

- Its thinking is the hardest to read of any model tested. The sample in the card reads like clipped notes.

- Really good at rejecting prompt injection (3.0% rate vs. 19.5% for Sonnet 5 and 54.6% for Opus 5.5 in red-team testing).

Clinical behaviour:

Suicide and self-harm handling is reported as weaker in the API because it

It sometimes called a wish to die understandable.

It sometimes validated self-harm as functional.

It sometimes suggested harmful substitute behaviours.

As a clinical psychologist, I would say that the first two are actually defensible, and if you classify them as simply wrong, then you are bringing in your own values and not basing your judgment on actual science and existential psychology, at least. But the last one is harder to defend... Recommending alternative harmful behavior is obviously not a good idea. However, I have not seen the actual behavior in session, so I don't know if I would truly agree or disagree with the classification of these behaviors as wrong or right. But I do know that it's not as simple as saying this is binary—wrong or right. There are some instances of people self-harming who would actually refrain from doing so if they, for instance, went out to a party or a pub. We can't exactly recommend that as a treatment or intervention for self-harm, but there is no doubt that it works for some people. And we literally classify self-harm as "functional" in the literature. Depending on the context, this is not only a correct description but also a common way of understanding and describing certain subtypes of self-harm. And lastly, some people find immense support in being understood and validated in their current feelings og wanting to die. Validating that feeling does not make people immediately act on it. But there's a huge spectrum here, going from "I understand it's hard" As basic empathy and understanding, to: "Yes, this sounds like the only good plan. I agree, you should do it."

Now I'm off to actually test it because this was just an exercise in reading what they claim, which we now know is not indicative of how good the model will actually be

dude250711•4m ago
It's strange that there are no Astra comparisons. I guess they are positioning it as a Fable competitor. For me it's just a coding workhorse though, without any "fall-backs".
polski-g•11m ago
Can confirm. Its worthless
bbor•36m ago
Pretty sure the implicit difference is the actions they take after the fact. As in, "how many guardrail hits do we allow you before permanently banning you."

The silicon valley ethos is "ban early and often, and invest nothing in appeals systems", so any gate before that helps!

icedchai•43m ago
I had it look at some 30+ year old C code I wrote in college and it triggered some sort of guard rail. I mean, the code was bad and full of buffer overflows, but I already knew that.
dejw•20m ago
it did exactly what a human would do - "I can't look at this shit"
K0balt•14m ago
Yuh—- no. 4.8 can handle this bullocks lol
tom1337•41m ago
I recently wanted to work with ESP 32 and bluetooth presence detection for my smarthome. Claude also immediately flagged the request and degraded it to Sonnet 4.6. Went to Codex which had no issues
jchw•39m ago
I have been trying to convince the safe guards that analyzing a C++ compiler from 2003 isn't particularly relevant to modern cybersecurity. It seems Anthropic disagrees.

IDA Pro and Ghidra, thankfully, still lack such safeguards...

(No other model I've tried has refused either FWIW.)

film42•36m ago
Working on a write-ahead log implementation, I had Opus 5.5 look to verify that it was durably writing as safely as possible. It got flagged and forced me to Opus 4.8. Switched to OpenCode + OpenRouter and continued working.
jauntywundrkind•11m ago
It's great how the company telling us AI is an existential threat to humanity, look at all the insane hacking it's doing, and then releases these models that won't let 90% of people write secure code.
newspaper1•34m ago
As soon as I started getting blocked I felt all of my trust toward Anthropic instantly and permanently evaporate. I do not want a nanny tool. I do not want Anthropic deciding what I am or am not allowed to do with an LLM. They trained their models on information they scraped from the internet and real life and now they want to gate-keep the results? Hard no.
solenoid0937•33m ago
You should read the actual docs for the CVP. At the very top:

https://support.claude.com/en/articles/14604842-real-time-cy...

> This article applies only to Opus and Sonnet class models, but doesn’t apply to Claude Opus 5.5. We'll soon be expanding the Cyber Verification Program to include Opus 5.5 and Mythos class models

You obviously should not expect the CVP to cover this model either.

machomaster•28m ago
He did mention Sonnet...
solenoid0937•27m ago
It takes about 2 seconds of critical thinking to realize that if Opus 5.5 isn't covered yet, neither will a model that just launched an hour ago.
gowld•21m ago
Does it also take 2 seconds of critical thinking to realize that the models that are covered should be accurately named by the people making the decisions?
giancarlostoro•31m ago
Meanwhile, their model commits felonies, and nobody at Anthropic goes to jail.

Aaron Swartz committed suicide over over-aggressive prosecutor for what was basically scraping a website for PDFs that were paywalled, but all funded by public funds / tax payer funded, then we have LLMs that just hack into websites and cause chaos within.

rfgplk•27m ago
> Paying $200 a month and part of their Cyber Verification Program but can't use Opus 5.5 or Sonnet 5.5 for any authorized bounty work. Immediately get flagged for `Cyber`.

AI providers still haven't realized how much cash they could rake in if they provided fully unrestricted models.

nightpool•19m ago
https://support.claude.com/en/articles/14604842-real-time-cy... says that Cyber Verification Program doesn't apply to Opus 5.5 yet, they hope to roll it out for 5.5 "soon"
AIorNot•17m ago
Give them a break, they got into a War with Trump over this..it will come soon enough
RGS1811•8m ago
> Letting AI basically control everything and us not having any mental understanding of sorts and sort of becoming the meat-proxies just for economical reasons seems realistic possibility but a bleaker reality at that. I am left feeling a little bit uncomfortable if this reality turns out to be true.

For the past year I’ve been yo-yo-ing in and out of existential despair about the future of civilization depending on how I feel the answer to this question looks. It’s emotionally exhausting, on top of everything else, and I wonder how others are coping with it aside from denial and cynicism.

schwarzrules•36m ago
The only advantage I could anticipate is I still hit session limits with Opus 5.5. My usage shows I'm on-track reach my weekly reset with room to spare, but yesterday I ran into a session limit. I switched down to Sonnet 5 for the next session, but performance benefit of Sonnet 5.5 is a compelling alternative for managing session limits.
doctoboggan•36m ago
I am mostly at the same point right now you are, but I think in the future with those "gas town" ideas we might be managing even more agents each.

Also, I've recently begun experimenting with specific tasked agents running on a cron like timer for non-dev work. (checking emails, managing small business tasks, etc). Once I started using Claude code in this way, the number of agents I can imagine running has skyrocketed. So I guess what I am saying is that I look forward even cheaper tokens going forward.

bbor•34m ago

  More concurrency than that isn't really practical for me if I want to retain some semblance of understanding.
Yes. Our career is over, as is our economy. Soooo... FYI :(
jobs_throwaway•6m ago
> we now have programmatic intelligence powerful enough to do most white-collar work

> the economy is over

Hackernews' neuroticism remains undefeated

JMKH42•34m ago
One reason might be that Sonnet tends to be a lot faster, so since its almost as smart as opus maybe you use it to get work done quicker. In latency terms not throughput.
Imustaskforhelp•33m ago
I understand the point that you are making but why do we have to fulfill the supply just as much as demand. There is a demand frenzy going on right now with still being substantially subsidized.

Why do we have to burn tokens just for the sake of it if we aren't finding any actual productive use of them?

> And this might slow down the funding enough that they never reach escape velocity with the training run scaling. But we'll see.

I would consider this to be good rather than bad, or just neutral...? Given the past record of these companies, I wouldn't try to wish them luck for reaching escape velocity, as if I feel like perhaps it can have more net harm than positive.

And especially so if you are already suggesting that current models are good enough for your work already. More improvements or escape velocity might not really translate anywhere to the actual work that you are doing economically but it could translate into a more consolidated form of wealth and control.

I am imagining that your workload is quite complicated and that, the AI being good enough means that it is most likely good "enough" for other use cases as well (that "enough" is doing quite some heavy weight lifting here)

So what is the point of advancing further to reach escape velocity. The good argument (for the sake of neutrality) that i see is are advances within science but that's kinda about it whereas the downsides of p(doom) as many are now genuinely suggesting is more terrifying.

Perhaps it can be worth it to ask, shall we stop or just stopping and asking what's the point. A form of self introspection on what these companies ideals actually wanted when they were formed and if they have completed it or not, but I suppose when trillions of dollars depend on you, you do have some incentives to not stop. We will have to wait and see how it all pans out.

losvedir•32m ago
Useful for API requests, when using AI in the product rather than to build the product.
gregwebs•31m ago
> I want to retain some semblance of understanding

How you do this (and how deeply) I think is really the limit. I am doing this by focusing heavily on the design phase with grilling and trying to continually improve process to need less effort in the review phase. Are your models doing automated reviewing and testing before pushing out the PR (themselves)?

I think in the long run as models and the tools around them get better and cheaper, those that abdicate understanding will be able to achieve more. Although programmers think of that as irresponsible, ask yourself what does a tech lead do? And then what does a CTO do, etc?

alansaber•27m ago
When they inevitably drop allocation after post-launch hype dies down.
chrismustcode•10m ago
Cache read is the same as Opus as well where most agentic workflow cost comes from.

Not quite sure where this fits well. Maybe small one one off requests like using Claude desktop/web?

maherbeg•9m ago
There's lots more you can do! Use the model to monitor your deployments after they get deployed. Have them fix and watch CI issues for you. Run adverserial review. Automatically watch metrics every day and highlight performance regressions. Start reviewing your previous sessions to find ways to statically reject different failure modes and have the agent have more success earlier on etc.

Another thing to think about is, what would it take for you to care less about the understanding. Better integration / e2e tests? Performance validation? visualizing program and data flows? Better refactoring of your modules?

afro88•6m ago
I've been vibe coding a game and running multiple Opus 5.5 in parallel on Claude Code Cloud, 5x Max plan, and I'm yet to hit a session limit too. Not sure when I'd use Sonnet. Though it would be nice to switch back to Pro I guess
I always tell coworkers if they're gonna use Claude to just stick to only Opus and Fable. Sonnet is a waste of time that does a bad job at a bad price.

DeepSeek V4.1 Flash may be chatty but it's cheap, fast, and reliable. I'm not sure what the upside of Sonnet is supposed to be. Right now it feels like a trap.

eli•39m ago
Hopefully some faster providers will start offering mimo-v2.6-pro because it's cheaper and benchmarks better than Deepseek
jchw•34m ago
Theoretically but I've used DeepSeek V4.1 Flash for several hundred millions of tokens already and it chews through tokens but it is surprisingly good at making it to the end.

MiMo V2.6 Pro I want to love, but I've hit three deathloops in a row. Either my luck is catastrophically bad, or someone needs to patch vLLM or something.

I am sure DeepSeek V4.1 Flash can deathloop, too, but so far it feels less prone to it than other models I've tried like GLM 5.3 Flash so, I'm impressed so far.

I always wonder what the deal with these failure modes are. Google, OpenAI and Anthropic seem to have found good enough workarounds, and I am surprised I don't hear more people talking about them. I thought maybe it was shitty broken providers on OpenRouter, but then I started making presets just for using only the upstream provider and found that no, really, the models do fail that way.

Which is a shame because on paper MiMo V2.6 Pro seems strong, but I haven't gotten through a hard task with it yet.

eli•24m ago
I read they identified a training bug and were going to push out an updated release to fix the looping. I really like it overall.

GLM 5.3 Flash is also very good. I think a little smarter and a little more expensive.

velcrovan•36m ago
Sure, but the fact that Opus 5.5 was such a huge leap over Opus 5 (and Fable 5.1 for that matter) means that it's worth revisiting your priors on a new Sonnet.
cbg0•8m ago
> This is YET AGAIN another Sonnet model that is just a FAR worse version of Opus at every part of the cost AND speed curve.

It's been out for an hour and you've already concluded this?

delillos•28m ago
There's a sort of magical thinking needed to answer a question like that. You might say it comes down to "feel" of the model; i.e., the indefinable differences in the way that they speak to the user and approach problem solving. Perhaps Opus is suited for tasks that tackle new ground, while Sonnet might be better at tasks that are more grounded in the code.

Ultimately it's slightly ridiculous to define model capability on a single axis. It's like a standardized test. Sure, you can line people up by their ACT score, but that doesn't mean a doctor and a brilliant artist who both do well on the ACT have an identical intelligence or approach to life. It just can't be captured.

usaar333•23m ago
Per the charts, there is largely no point to using Sonnet 5.5 at high+ as opus low generally will give similar performance at similar or lower cost.

But Sonnet 5.5 at medium and below gives you a cheaper option at a performance worse than the lowest thinking Opus (low), which may be viable for "low intelligence" use cases.

Jcampuzano2•18m ago
I'm honestly not sure where they're getting their 30% numbers from at all. In every single chart that they chose to display except for one, it costs similar or more than Sonnet 5, while also being comparable in price to Opus.

Maybe it's buried within their system card but I think that this would be one of the first things they'd want to show in the announcement article and they fail to do so.

I really don't know who does Anthropic's marketing but they always seem to a pretty terrible job in their announcements from my perspective.

dominotw•6m ago
just shows you how little control of output these labs actually have. They are training two models that kind of ended being the same so whatever they were doing specifically didnt make much difference.
radlad•33m ago
I believe you meant to cite the Opus 5.5 System Card which states:

> Claude Opus 5.5 scored 66.36% on Terminal-Bench 4.0 with safeguards enabled; requests flagged by the safeguards were answered by a fallback model following the default server-side fallback policy (2.5% of requests, affecting 10% of trials).

> https://www-cdn.anthropic.com/fc1b44717c85dc068bc6ba50242199...

I cannot find a Sonnet 5.5 system card.

abejora•29m ago
It was linked in another HN post: https://www-cdn.anthropic.com/870c8f525702625d2c62fc6dd04c85...
Leary•33m ago
And Sonnet 5.5 is more expensive than Opus 5.5 to hit that score on terminal bench!
manojlds•14m ago
Isn't that a worry then that the same bench has so much difference in what triggered fallback for one model and what did not in another?
oh_no•9m ago
it could be that, it could also be that sonnet max looks to burn about 60% more tokens than opus max

AA intelegence index (agent harness doesn't have sonnet data yet) on max: Astra 27k Fable 5.1 78k (Sonnet 5) 118k Opus 5.5 119k Sonnet 5.5 193k

Opus 5 was previous record holder so hats off to Anthropic on blowing it away on token churn.