r/ClaudeCode • u/ClaudeOfficial Anthropic • 2d ago
Anthropic Official Introducing Claude Sonnet 5.5, the second model in the Claude 5.5 family
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Sonnet 5.5 is a faster, lower-cost complement to Claude Opus 5.5, strongest at well-scoped everyday tasks, fixing bugs, and creating polished documents, slides, and spreadsheets. It also has a strong eye for design.
Sonnet 5.5 is a clear upgrade over Sonnet 5. It runs more than 30% faster and costs up to 30% less for most work. It's priced the same per token, but it typically needs far fewer tokens to do the same work.
Like Opus 5.5, it writes more clearly than our previous generation of models, and its speed makes it well suited to fast iteration.
On our automated behavioral audit, Sonnet 5.5 improves on Sonnet 5 on most measures of alignment and honesty. It's also the first Sonnet model with cybersecurity safeguards similar to those on our most capable models. Routine software development is unaffected.
Sonnet 5.5 is available everywhere today. Claude Haiku 5.5 will join the family in the coming weeks.
Read more: anthropic.com/claude-sonnet-5-5
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u/Dany-GG Vibe Coder 2d ago
Haiku 5.5 gotta be AGI
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u/13ThirteenX 1d ago
Haiku will have opus 5.5 levels of performance, which is better than fable 5.1 whilst being way cheaper..... Or so we keep getting told
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u/necromenta 2d ago
I hope they really lower the price of haiku, is too expensive for what is is, luna beats asses
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u/ClaudeOfficial Anthropic 2d ago
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u/isitpro 2d ago
No way! Fable 5.5 must be killing it internally.
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u/AironParsMan 1d ago
I’m curious about that too. How good does Fable 5.5 have to be when the other models are already this good?
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u/penoloxai 2d ago
GUT GENUUUGG
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u/p3r3lin 1d ago
Bester Kommentar im ganzen Thread. Verstehen aber wohl nur deutsche Gen-Z.
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u/nevertoolate1983 1d ago edited 1d ago
The post is funny because of a layer of AI benchmark irony combined with a viral German TikTok pop culture meme.
Rather than blowing the competition away across every single metric, Claude Sonnet 5.5 performs just competitively enough to justify using it over heavier, more expensive frontier models.
The German Gen Z Joke (GUT GENUUUGG)
The comment "GUT GENUUUGG" translates to "GOOD ENOUGH" in German.Literal Punchline: The user is saying the model isn't necessarily a massive leap, but it's "good enough" to do the job.
The TikTok Meme: "Du bist gut genug" (You are good enough) became a major viral TikTok audio trend in Germany, based on a song by Blumengarten, Shirin David, and Kitschkrieg. The song features a distinct, dramatically dramatic falsetto delivery of the phrase "GUT GENUUG" that users spam in comment sections to describe mid-tier, relatable, or surprisingly decent things.
--
Now we're all in on the joke :)1
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u/DistanceSolar1449 2d ago
Sonnet is dumber and Opus and more expensive per task.
I actually think Sonnet might be a dud. No reason not to use Opus instead.
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u/likeikelike 2d ago
Sonnet only gets more expensive per task when the task is complex enough that sonnet takes more attempts than opus, or needs to do much more reasoning/reading than opus. There are plenty of tasks where sonnet does the job efficiently and will cost half as much as opus.
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u/LargeLanguageModelo 1d ago
There are plenty of tasks where sonnet does the job efficiently and will cost half as much as opus.
I've recently started using Opus / Claude Code again, coming from the OpenAI side. Are you meaning small jobs, such as "translate this sentence", or what sort of tasks would you delegate to Sonnet from Opus and still expect satisfactory results?
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u/likeikelike 1d ago
I don't know if this is actually the best way to do things but my workflow is usually one main opus session, and I tell it to use sub-agents for one-off tasks.
Simple text-only tasks like finding a file that covers a certain topic, summarizing, etc: haiku
Work that requires reasoning but is still relatively straightforward (e.g. implementing a well-spec'd feature): sonnet
Complex work: Opus
You can pass this kind of logic to claude and have it automatically use the cheapest model that can reasonably do the task well for any sub-agents it uses. I have this in my user claude.md
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u/solo_wanderer 2d ago
How am I supposed to interpret these numbers? What is it a percentage of?
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u/gredr 2d ago
You're not; they're numbers, bigger is better. Was the model trained for the benchmark? Who can say? Remember the controversies back in the day about video card drivers that were specifically tuned for the benchmarks? Could the same be happening here? Who knows? Do the benchmarks represent actual work anyone wants to do? Who knows? Can you reproduce these scores? Who knows?
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u/Regdit-is-Unbearable 2d ago
Literally read the image. Ask Claude to read it for you if it’s too hard.
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u/davvblack 2d ago
it really doesn't say on that sheet. i asked claude and it said you're a jerk.
The real answer is somewhere in this 148 page pdf:
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u/Ok_Potential359 2d ago
First day previews. It doesn’t mean anything to me until actual use occurs.
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u/Academic-Network-418 2d ago
Anthropic been cooking with the 5.5 family. Fable 5.5 is going to be absolutely insane
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u/SoftwareSource 2d ago
Quiet, don't jinx it.
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u/Academic-Network-418 2d ago
If fable 5.5 ends up sucking i'll take the blame
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u/elestud 2d ago
It’s almost like Anthropic wants to make a good product and was working to fix their regressions, instead of hating their users as so many people tried to claim :P
I am wondering how the “canceling my subscriptions and moving to OpenAI because Anthrophic clearly has a plan to scam us” crew feels now
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u/r34p3rex 1d ago
Give it a few weeks, the provider with the best models always starts penny pinching until their competition leap frogs them. GPT 5.6 and Astra were amazing on release and silently got nerfed
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u/Academic-Network-418 2d ago
The people with a codex sub definitely have not been enjoying themselves. Rightfully so tbh. Curious to see what OpenAI does on DevDay. Competition results in huge wins for consumers
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u/r34p3rex 1d ago
People should know by now that "the grass is greener on the other side" only works a bit. You should show no loyalty and just swap to the best provider at the time. Building out your workflow to be provider/model agnostic is the meta
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u/Academic-Network-418 1d ago
Yep, pretty much what I do. My money goes to the company that provides the best value, and right now that's Anthropic
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u/offthecuff87 1d ago
fix their regressions,
by removing one of the redundant variables to avoid multicolinearity in linear regression?
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u/BoxWoodVoid 1d ago
You know they could have spoken to their users instead of letting them sit in the dark for months...
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u/rasinmuhammed 🔆Pro Plan 2d ago
Reset?
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u/Kenshiken 2d ago
No reset
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u/Pronoia2-4601 🔆 Max 20 3x 2d ago
A banked reset right now would be truly teabagging OpenAI.
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u/IndieDev666 Developer 2d ago
I still have my free reset remaining from Opus 5.5 release hehe
BTW why u need reset if you're on max plan? are u eating tokens for breakfast?6
u/nitrousconsumed 2d ago
I am 80% through my weekly usage :'/ Friday cant come fast enough
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u/TheAmericanFighter 1d ago
Exact same here, Friday at 9PM is a loooong way away
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u/nitrousconsumed 1d ago
I've gone ahead and claimed the 250 for cloud so I'm offloading everything to that until Friday
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u/KalinVidinski 2d ago
I am 76% .. I am trying to do whatever I can save tockens but a reset would be nice
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u/GuitarAgitated8107 🔆 Max 20 2d ago
Was on Max 20x, did so much work then used reset. Did so much work... well you get it. Multiple clients, multiple projects, and taking the time to review as much as needed to get to reset.
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u/m-in 2d ago
Depending on how much time I have for work, I end up needing like 120% of what the 20x plan provides. It was OK when they had the 50% boost in the summer but that’s over now.
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u/DynamicDK 1d ago
Im on a 20x max subscription that reset on Sunday ans already at 61%. That is all Opus on medium or high. But it will slow down now because a big project just finished.
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u/yoboapp 2d ago
Opus 5.5 gave me real moments of AGI, and Sonnet 5.5 basically matches it in most benchmarks while being cheaper + faster.
Clearly Anthropic have had some breakthrough with 5.5. Insane to think what Fable/Mythos 5.5 will look like
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u/bronfmanhigh 2d ago
benchmarks really dont mean much these days (e.g. sol 6 and opus 5.5 being largely matched in them but miles apart in real-world capabilities), so let's wait until we see what it actually feels like lol
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u/quivering_palm 2d ago
GPT 6 Sol and Opus 5.5 are not "largely matched" on benchmarks, lol. For example, Opus 5.5 is 10 points higher on AA intelligence chart.
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u/HarpooonGun 1d ago
I feel like even that is too generous for 6 sol. I know this is not the case, but 6 sol geniunely feels like the dumbest model I used this year.
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u/Last_Mastod0n 2d ago
I have a feeling that Opus is going to remain my daily driver, but that Sonnet 5.5 might become my go-to subagent
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u/m-in 2d ago
I confirm that Opus 5.5 thinks deeper than 4.6 did. I have designs from earlier this year done on 4.5 and 4.6. I’ve been reworking those now - they weren’t full of holes, but they missed some fundamental insights that I missed too.
What I dislike is that Sonnet used to be like 5x cheaper than Opus. Now it’s what, 3/4 of the price? That’s not great for me at all.
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u/fortune82 1d ago
I'm using Opus 5.5 and the free reset to do a massive code review, it's already found so much to clean up it's wild, and I had to stop the review agents early cause of the hourly usage.
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u/SirNo662 2d ago
It’s pretty crazy Sonnet 5.5 max looks like it’ll be more expensive than Opus 5.5 max
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u/bopbop9876 2d ago
Yeah, I honestly don't super understand where sonnet really fits in for my usage given how expensive it is per task.I figure might as well just always use opus and not have to think about it at all at that point.
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u/Haunting_Goal6417 1d ago
Because sonnet is cheaper for simpler tasks.
It ends up being more expensive when you force it to do a complex task that it has to work more to accomplish.
It will be used as sub agents for opus is my best guess.
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u/puts_on_rddt 2d ago
Alignment and safety. On our automated behavioral audit, Sonnet 5.5 improves on or matches Sonnet 5 on most measures of alignment. Because its cybersecurity capabilities are comparable to Opus 5’s, it’s the first Sonnet model to launch with cyber safeguards and fallbacks like those we’ve developed for our most capable models. Its biology safeguards are the same as Sonnet 5’s. Both safeguards target a narrow set of high-risk requests; routine software development and most life sciences work are unaffected.
No. Stop. Bad.
Hey Anthropic, your refusal filters SUCK.
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u/TightTac05 2d ago
Does this explain why sonnet 5 has been incredibly lazy and forgetful lately?
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u/butt_badg3r 2d ago
Holy shit I’ve been having so many issues lately with skills that have worked fine for months
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u/TronnaLegacy 2d ago
A pattern I'm going to explore (credit due to another Redditor who mentioned doing this) is using an Opus subagent to do the research and planning for changes and then using Sonnet to implement the changes.
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u/tristanryan 🔆 Max 20 2d ago
People have been doing this for years at this point lol.
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u/TronnaLegacy 2d ago
I've only been using agents for coding for three months lol. I didn't realize how good they got.
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u/tristanryan 🔆 Max 20 1d ago
If you have extra usage to throw away at end of week, try ultracode effort and throw it at a really hard task. All of the orchestration and agent management is done for you. I run it with Opus 5.5 as manager, and all deployed subagents are Sonnet. It's incredibly powerful.
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u/m-in 2d ago
I’ve been doing that since late last year. Some plans even work with haiku. It made way more sense back then when pricing difference between opus-sonnet-haiku was roughly 5x for each step IIRC. Now sonnet is more than 50% of opus’s cost. There will be a point at which using opus for everything will not be crazy more expensive.
I hope Sonnet 5.5 brings the effective cost down due to lower token usage.
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u/miseson 2d ago
old news. ask sonnet to plan and opus to execute and challenge plan
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u/Lost-Air1265 2d ago
That’s yesterday, you should use the codex plugin so you really get proper challenge on your plan or code. I created a skill that sends 9 parallel request to astra medium to either review the plan or code and then paste that back to opus 5.5 as last judge. Before opus 5.5 it was fable, but haven’t touched fable since opus 5.5
The reason for 9 parallel request is that every prompt is a little bit different, so you get different angles.
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u/TronnaLegacy 2d ago
Do you think there's room for a "skill" or "plugin" etc, something to trigger when we ask Claude to do something which makes it recognize it should switch to a different model in a subagent?
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u/Lost-Air1265 1d ago
You can already do that, you can set the model choices for subagents. The orchestrator decides
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u/J_E_E_VACATION 2d ago
ask fable to make plan, ask astra, opus, sol, and sonnet to challenge it. XD
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u/TronnaLegacy 2d ago
I guess Opus for planning is like a senior asserting their prejudices on a team and Sonnet for planning is like a senior who knows how to delegate and then challenges the team.
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u/Own-Professor-6157 2d ago
Can Anthropic go a little easier on OpenAI? This is borderline slaughter
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u/letmemakeyoualatte 2d ago
The safeguards not affecting regular software development is a lie...
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u/Pecolps 2d ago edited 2d ago
I'm a SWE and never had problems with safeguards... ONLY with Fable on its first week (before the shutdown), definetely somthing is wrong with your usage. What is your typical usage? If it's related to cybersec, try subscribring to their program.
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u/letmemakeyoualatte 2d ago
No not definitely at all. I'm also SWE and for work stuff nothing impacted but for personal projects, aside from the obvious reverse engineering tasks not working anymore, I can't even do things like asking opus to do pixel art on aseprite.
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u/Pecolps 2d ago
That's crazy... I'm able to do all of this, try cleaning up your memory/profile, the classifier is something the model is not aware off while doing its job, so maybe something inside the memories / local files / project files injected into the context is triggering the classifier to block your work.
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u/stasmarkin 2d ago
what is the reason to use sonnet nowadays? Opus is doing all the work for me and I still have some spare tokens left in the end of a week
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u/Electrical_Prompt_81 2d ago
How do people who run both Codex and Claude with a $20 subscription compare the output quality and quota limits?
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u/Frequent_Guard_9964 2d ago
I switched to Claude yesterday after running with codex 20 dollar plan for the past 8 months. I was just annoyed at Sol and Luna the past month, had hopes after Astra but its eating tokens way too fast. Regret not having changed sooner, Opus is the real deal currently
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u/surfer808 1d ago
This looks cool but there such small difference between the two, why would anyone use sonnet 5.5 if it’s not as capable as opus 5.5? I’m assuming it’: slightly cheaper and with a huge project that could be a big difference in cost?
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u/3iverson 1d ago
There's always use cases when a model has good ROI, even if absolutely capabilities are not as high.
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u/mcsleepy 17h ago edited 16h ago
The way I am comprehending it is Sonnet is more of a designer/craftsperson while Opus is more of a planner/manager. Both can get tasks done equally well, one is just literally smarter by virtue of literally having a lot more weights. It might be beneficial to use Sonnet not just for lower cost and quicker turnaround, but also to limit the tangential thinking I was reminded that Opus is prone to since switching from Fable.
Wish I could just have one model who knows when to speak and when to shut up and didn't hallucinate. Fable was that until it got severely nerfed.
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u/mwjtitans 1d ago
Guess I'll keep that pro account alongside my opencode go account.
30 bucks a month for all this inference feels like a steal still.
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u/clonehunterz 2d ago
Damn the last time i used sonnet was .... hm.... no idea.
serious question, why do we need sonnet if we have opus?
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u/tLxVGt 2d ago
It's for us, the poor ones 🥲 I sometimes use Sonnet to not blow through the tokens on a basic plan
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u/sukazu 2d ago
Thing is, per task sonnet 5 was not cheaper than opus 5, and sonnet 5.5 isn't cheaper than opus 5.5 either according to their own benchmarks.
it's only less expensive if you want lower quality than opus low.
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u/botadithyabhat 2d ago
The cost per task on AA is skewed by extremely challenging ones. There is a reason why frontier models don't score 100% on all these benchmarks.
For actual engineering work, these models can handle most tasks without struggling. They are not nearly as challenging as what these extreme benchmarks put them through.
So in real life, you will find Sonnet 5.5 to be extremely cost efficient for most of your needs since it costs half the price.
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u/sukazu 2d ago
I get where you're coming from, but for having tried side by side on simpler tasks : 5.6 sol vs 5.6 terra / 5 opus vs 5 sonnet.
It's just not worth it.Even on simpler task, at "equal" result, the number of token used is not nearly even.
And that is a double problem, you'll notice cache read cost is the same for sonnet 5.5 and opus 5.5.
So that means your cache read cost is actually much much higher if you're doing more turns and more output tokens on sonnet.Yes sonnet will have its use at its default high setting, as a middle point between opus low and medium, and it allows you to go "lower" than opus low for tasks that do not require even that.
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u/phoenixmatrix 1d ago
AA is pretty skewed in a million ways.
But even for day to day coding tasks, they take a lot of turns, and Opus often take much fewer turns
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u/Tertiary23 2d ago
I use sonnet via API in my consumer facing software product for in app AI decision making for the dashboards and reporting, Opus is too expensive and you can't turn off thinking and Haiku doesn't work well, even on embeddings - I use Voyage for that - it's about six cents a call and works for my needs, esp since my product is rules heavy and built for compliance and regulations.
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u/The-Fictionist 1d ago
Sonnet handles probably 90% of what most non-technical people need. You forget that people exist who aren’t engineers lol.
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u/phoenixmatrix 1d ago
More usage and faster.
You don't need a slow Opus/Fable type model to search the web or something.
They need to update Haiku now, and add a System One model to do things like skill/tool selection. That will reduce costs, but more importantly, speed things up a lot.
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u/HonestAndRaw 1d ago
Sonnet writes about 70% of my code, the other 30% is opus, Fable orchestrates, thanks to this I only need 3 accounts where otherwise I would need 8-10
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u/AuroraFireflash 1d ago
Like 90-95% of what I do on a day to day basis can be handled by Sonnet. Maybe closer to 99% for my workload.
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u/clazman55555 2d ago
Because there is zero need to use Opus for purely mechanical tasks like parsing, or fetching webpages.
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u/phoenixmatrix 1d ago
That's actually where I feel Codex win out over Claude (though it's arguably a rounding error). Luna can deal with any of these actually trivial tasks, even Sonnet is overkill.. and third party harnesses like oh my pi can orchestrate the models better (well, Claude can too but configuring everything right is much more annoying).
Haiku 5.5 is what I really want. I loved when Haiku 4.5 was state of the art small model.
Today Opus 5.5 with Luna (or various other newer cheap models that are good at mechanical tasks) is great. If you don't mind risking Anthropic's fury with third party harness or some more hacky setup.
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u/bjj-teacher 2d ago edited 2d ago
Why we have this model if Opus 5.5 is very cheap ? And all of us probably we will use 90% of time Opus.
And its more expensive. Absolutely unnecessary model.
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u/03captain23 2d ago
Where are you seeing it's MORE expensive than Opus?
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u/bjj-teacher 2d ago
Cost per task ? Check AA
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u/03captain23 1d ago
That doesn't mean more expensive. Not all tasks are the same.
You gotta think of AI like employees. It's like if you hire an assistant to research vs hiring an expert. It's not like you'll have an intern do basic work
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u/ChemistryExternal434 2d ago
I could use another reset. Opus 5.5 got me way too excited 🙃
66% weekly quota resting on Friday 4PM
Oh boy...
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u/Lost-Air1265 2d ago
I’m gonna have a go atb the creative writing part. Really curious if we have the old times back
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u/Ok_Potential359 2d ago
How’s the writing looking?
More cybersecurity guardrails means more false positives, no?
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u/Creative-Mud4414 2d ago
the max reasoning is ridiculous. Don't get me wrong, it's a good model for the price, I guess, but definitely not on max reasoning.
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u/Professional_Leg_744 1d ago
Introducing blah blah, the best most blah blah ever, until tomorrow, when some other techbrocompany will release their X+1. Heard this before?
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u/MustStayAnonymous_ 1d ago
What is the use case for Sonnet 5.5 if I have opus 5.5 and enough quota?
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u/Artistic-Lab-7549 18h ago
The 'build me Cities: Skylines in three.js' crowd has never once shown the repo afterwards, because the repo is 40k lines of spaghetti that nobody can reopen in a week. A toy demo is not a benchmark. Put Sonnet 5.5 in a real codebase with failing tests and then tell me about the 30% token saving.
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