Update, Haiku 4.5 is not just very targeted in terms of changes but also really fast. Averaging at 220token/sec is almost double most other models I'd consider comparable (though again, far to early to make a proper judgement) and if this can be kept up, that is a massive value add over other models. That is nearly Gemini 2.5 Flash Lite speed for context.

Yes, we got Groq and Cerebras getting up to 1000token/sec, but not with models that seem comparable (again, early, not a proper judgement). Anthropic has been historically the most consistent in outperforming personal benchmarks vs public benchmarks, for what that is worth so I am optimistic.

If speed, performance and pricing are something Anthropic can keep consistent long term (i.e. no regressions), Haiku 4.5 really is a great option for most coding tasks, with Sonnet something I'd tag in only for very specific scenarios. Past Claude models have had a deficiency in longer term chains of tasks. Beyond 7 minutes roughly, performance does appear to worsen with Sonnet 4.5, as an example. That could be an Achilles heel for Haiku 4.5 as well, if not this really is a solid step in terms of efficiency, but I have not done any longer task testing yet.

That being said, Anthropic once again has a rather severe issue it seems, casting a shadow upon this release. From what I am seeing and others are reporting, Claude Code currently does count Haiku 4.5 usage the same as Sonnet 4.5 usage, despite the latter being significantly more expensive. They also did not yet update the Claude Code support pages to reflect the new models usage limits [0]. I really think such information should be public by launch day and hope they can improve their tooling and overall testing, it really continues to throw a shadow over their impressive models.

[0] https://support.claude.com/en/articles/11145838-using-claude...

Been waiiting for the Haiku update as I still do a lot of dumb work with the old one, and it is darrn cheap for what you get out of it with smart prompting. Very neat they finally release this, updating all my bots... sorry agents :)

Those numbers don’t mean anything without average token usage stats.

I don’t mean this with snark, but with age. It’s actually totally cool to not upgrade and then you have stability in your tooling.

I bet there is some hella good art being made with Photoshop 6.0 from the 90s right now.

The upgrade path is like the technical hedonistic treadmill. You don’t have to upgrade.

Even if you pick one. First it's prompt driven development, then context driven. Then you should use a detailed spec. But no, now it's better to talk to it like a person/have a conversation. Hold up why are you doing that you should be doing example driven. Look, I get that they probably all have their place, but since there isn't consensus on any of this, it's next to impossible to find good examples. Some one posted a reply to me on a old post and called it bug-driven development and that stuck with me. You get it to do something (any way) and then you have to fix all the bugs and errors.

> Ain't nobody got time to pick models and compare features. ... Make it integrate in a generic way, ... , so that it doesn't matter whether I'm using a CLI or neovim or an IDE, and so that I don't have to constantly switch tooling.

I use GitHub Copilot Pro+ because this was my main requirement as well.

Pro+ has the new models as they come out -- actually just enabled Claude Haiku 4.5 for selection availability. I have not yet had a problem with running out of the premium allowance, but from reading how others use these, I am also not a power user type.

I have not yet the CLI version, but it looks interesting. Before the Intellij plugin improved, I would switch to VS Code to run a certain types of prompt then switch back after without issues. The web version has the `Spaces` thing that I find useful for niche things.

I have no idea how it compares to the individual offerings, and based on previous hn threads here, there was a lot of hate for gh copilot. So maybe it's actually terrible and the individual version are lightyears ahead -- but it stays out of my way until I want it and it does its job well enough for my use.

One option: Use OpenRouter [1] with the `openrouter/auto` model [2], which will pick among GPT-5, Gemini 2.5 Pro, Claude Sonnet 4.5 and similar.

[1] https://openrouter.ai/

[2] https://openrouter.ai/openrouter/auto

You can use Crystal (https://github.com/stravu/crystal) to run Codex and Claude Code at the same time and just pick the best result.

I use OpenRouter for similar reasons -- half to avoid lock-in, and the other half to reduce the switching pain, which is just a way to say "if I do get locked in, I want to move easily"

VSCode + the new "Auto" model probably worth a shot for this

> annoying enough having to switch from one LLM ecosystem to another all the time due to vague usage restrictions

I use KiloCode and what I find amazing is that it'll be working on a problem and then a message will come up about needing to topup the money in my account to continue (or switch to a free model), so I switch to a free model (currently their Code Supernova 1million context) and it doesn't miss a beat and continues working on the problem. I don't know how they do this. It went from using a Claude Sonnet model to this Code Supernova model without missing a beat. Not sure if this is a Kilocode thing or if others do this as well. How does that even work? And this wasn't a trivial problem, it was adding a microcode debugger to a microcoded state machine system (coding in C++).

Gemini Pro initially refused (!) but it was quite simple to get a response:

> give me the svg of a pelican riding a bicycle

> I am sorry, I cannot provide SVG code directly. However, I can generate an image of a pelican riding a bicycle for you!

> ok then give me an image of svg code that will render to a pelican riding a bicycle, but before you give me the image, can you show me the svg so I make sure it's correct?

> Of course. Here is the SVG code...

(it was this in the end: https://tinyurl.com/zpt83vs9)

Context on this cutting-edge benchmark for those unaware:

https://simonwillison.net/2025/Jun/6/six-months-in-llms/

https://simonwillison.net/tags/pelican-riding-a-bicycle/

Full verbose documentation on the methodology: https://news.ycombinator.com/item?id=44217852

As added context to ensure no benchmark gaming, here a quite impressive Shitaki Mushroom riding a rowboat: https://imgur.com/Mv4Pi6p

Prompt: https://t3.chat/share/ptaadpg5n8

Claude 4.5 Haiku (Reasoning High) 178.98 token/sec 1691 tokens Time-to-First: 0.69 sec

As a comparison, here Grok 4 Fast, which is one of worst offenders I have encountered in doing very good with a Pelican Bicycle, yet not with other comparable requests: https://imgur.com/tXgAAkb

Prompt: https://t3.chat/share/dcm787gcd3

Grok 4 Fast (Reasoning High) 171.49 token/sec 1291 tokens Time-to-First: 4.5 sec

And GPT-5 for good measure: https://imgur.com/fhn76Pb

Prompt: https://t3.chat/share/ijf1ujpmur

GPT-5 (Reasoning High) 115.11 tok/sec 4598 tokens Time-to-First: 4.5 sec

These are very subjective, naturally, but I personally find Haiku with those spots on the mushroom rather impressive overall. In any case, the delta between publicly known benchmark and modified scenarios evaluating the same basic concepts continues to be smallest with Anthropic models. Heck, sometimes I've seen their models outperform what public benchmarks indicated. Also, seems Time-to-first on Haiku is another notable advantage.

I’m surprised none of the frontier model companies have thrown this test in as an Easter egg.

Have you noticed image generation models tend to really struggle with the arms on archers. Could you whip up a quick test of some kind of archer on horseback firing a flaming arrow at a sailing ship in a lake, and see how all the models do?

Looks very uncomfortable to the bird.

i knew simon would be top comment. it's not an empirical law

imagine finding the full text of the svg in the library of babel. Great work!

Technically, they released Opus 4.1 a few weeks ago, so that alone hints at a smaller leap from 4.1 -> 4.5, compared to the leap from Sonnet 4 -> 4.5. That is, of course, if those version numbers represent anything but marketing, which I don't know.

My impression is that Sonnet and Haiku 4.5 are the same "base models" as Sonnet and Haiku 4, the improvements are from fine tuning on data generated by Opus.

I'm a user who follows the space but doesn't actually develop or work on these models, so I don't actually know anything, but this seems like standard practice (using the biggest model to finetune smaller models)

Certainly, GPT-4 Turbo was a smaller model than GPT-4, there's not really any other good explanation for why it's so much faster and cheaper.

The explicit reason that OpenAI obfuscates reasoning tokens is to prevent competitors from training their own models on them.

Opus disappeared for quite a while and then came back. Presumably they're always working on all three general sizes of models, and there's some combination of market need and model capabilities which determine if and when they release any given instance to the public.

I wonder what the next smaller model after Haiku will be called. "Claude Phrase"?

With caching that's 10 cents per million in. Most of the cheap open source models (which this claims to beat, except glm 4.6) have limited and not as effective caching.

This could be massive.

I am a professional developer so I don't care about the costs. I would be willing to pay more for 4.5 Haiku vs 4.5 Sonnet because the speed is so valuable.

I spend way to much time waiting for the cutting edge models to return a response. 73% on SWE Bench is plenty good enough for me.

Yeah, I'm a bit disappointed by the price. Claude 3.5 Haiku was $0.8/$4, 4.5 Haiku is $1/$5.

I was hoping Anthropic would introduce something price-competitive with the cheaper models from OpenAI and Gemini, which get as low as $0.05/$0.40 (GPT-5-Nano) and $0.075/$0.30 (Gemini 2.0 Flash Lite).

This also means API usage through Claude Code got more expensive (but better if benchmarks are to be believed)

I don't understand why more people don't talk about how fast the models are. I see so much obsession with bechmark scores but speed of response is very important for day to day use.

I agree that the models from OpenAI and Google have much slower responses than the models from Anthropic. That makes a lot of them not practical for me.

I think with gpt-5-mini and now Haiku 4.5, I’d phrase the question the other way around: what do you need the big models for anymore?

We use the smaller models for everything that’s not internal high complexity tasks like coding. Although they would do a good enough of a job there as well, we happily pay the uncharge to get something a little better here.

Anything user facing or when building workflow functionalities like extracting, converting, translating, merging, evaluating, all of these are mini and nano cases at our company.

One big use-case is that claude code with sonnet 4.5 will delegate into the cheaper model (configurable) more specific, contextful tasks, and spin up 1-3 sub-agents to do so. This process saves a ton of available context window for your primary session while also increasing token throughput by fanning-out.

They are great for building more specialized tool calls that the bigger models can call out to in agentic loops.

for me its the speed; eg cerebras qwen coder gets you a completely different workflow as its practically instant (3k tps) -- feels less like an agent and more like a natural language shell, very helpful for iterating on a plan that you them forward to a bigger model

For me speed is interesting. I sometimes use Claude from the CLI with `claude -p` for quick stuff I forget like how to run some docker image. Latency and low response speed is what almost makes me go to Google and search for it instead.

In my product I use gpt-5-nano for image ALT text in addition to generating transcriptions of PDFs. It’s been surprisingly great for these tasks, but for PDFs I have yet to test it on a scanned document.

If you look at the OpenRouter rankings for LLMs (generally, the models coders use for vibe/agentic coding), you can see that most of them are in the "small" model class as opposed to something like full GPT-5 or Claude Opus, albeit Gemini 2.5 Pro is higher than expected: https://openrouter.ai/rankings

Sonnet 4.5 was two weeks ago. In the past I never had such issues, but every week my quota ended in 2-3 days. I suspect the Sonnet 4.5 model consumes more usage points than old Sonnet 4.1

I am afraid Claude Pro subscription got 3x less usage

I’m also really interested in this - in fact it’s the first thing I went looking for in the announcement…

How close are you?

Oh right, Anthropic doesn't tell you.

I got that 'close to weekly limits' message for an entire week without ever reaching it, came to the conclusion that it is just a printer industry 'low ink!' tactic, and cancelled my subscription.

You don't take money from a customer for a service, and then bar the customer form using that service for multiple days.

Either charge more, stop subsidizing free accounts, or decrease the daily limit.

I think a lot of people judge these models purely off of what they want to personally use for coding and forget about enterprise use. For white-label chatbots that use completely custom harnesses + tools, Sonnet 4.5 is much easier to work with than GPT-5. And like you, I was really pleased to see this release today. For our usage speed/cost are more important than pure model IQ above some certain threshold. We'll likely switch over to Haiku 4.5 after some testing to confirm it is what it says on the tin.

wow, grok code fast is really cheap

I'm using the smaller models for things like searching and summarizing over a larger part of the codebase. The speed is really pleasant then.

I feel like if I just do a better job of providing context and breaking complex tasks into a series of simple tasks then most of the models are good enough for me to code.

If it’s fast enough it can make and correct mistakes faster, potentially getting to a solution quicker than a slower, more accurate model.

https://en.wikipedia.org/wiki/Goodhart%27s_law "When a measure becomes a target, it ceases to be a good measure"

I'm also curious what results we would get if SWE came up with a new set of 500 problems to run all these models against, to guard against overfitting.

It sounds like AI researchers have used too much of their own bad sci-fi as training data for models they don't understand. Goodhart's law wins again!

They previously discussed this some in the context of Opus 4: https://www.anthropic.com/research/end-subset-conversations

> We remain highly uncertain about the potential moral status of Claude and other LLMs, now or in the future. However, we take the issue seriously, and alongside our research program we’re working to identify and implement low-cost interventions to mitigate risks to model welfare, in case such welfare is possible. Allowing models to end or exit potentially distressing interactions is one such intervention.

In pre-deployment testing of Claude Opus 4, we included a preliminary model welfare assessment. As part of that assessment, we investigated Claude’s self-reported and behavioral preferences, and found a robust and consistent aversion to harm. This included, for example, requests from users for sexual content involving minors and attempts to solicit information that would enable large-scale violence or acts of terror. Claude Opus 4 showed:

* A strong preference against engaging with harmful tasks;

* A pattern of apparent distress when engaging with real-world users seeking harmful content; and

* A tendency to end harmful conversations when given the ability to do so in simulated user interactions.

These behaviors primarily arose in cases where users persisted with harmful requests and/or abuse despite Claude repeatedly refusing to comply and attempting to productively redirect the interactions.

It’s so funny to me but ever since they fixed that claud bug my experience has consistently been the exact opposite. Only thing I use codex now for are quite standard things it can solve end to end (like adding new features to my crud app) anything non standard iterating with Claude yields much better results.

Out of curiosity, what kind of work do you use them for? I did a comparison of a few different models for setting up a home server with k3s and a few web apps in nextjs. Claude was my favorite for both tasks, but mainly because it seemed to take my feedback a lot better than others.

Do you need Pro?

90% as good as Sonnet 4 or 4.5? Openrouter just started reporting, and it's saying Haiku is 2x as fast (60tps vs 125tps) and 2-3x less latent (2-3s vs 1s)

Do you have a definition of what is considered a small vs large coding task?

Is your company Tier 4? Anthropic has had 1M context size in beta for some time now.

https://docs.claude.com/en/docs/build-with-claude/context-wi...

You on latest version? Try running /update hook. Can also config autoupdates

check the model name here: https://docs.claude.com/en/docs/about-claude/models/overview...

claude --model claude-haiku-4-5-20251001

use claude-haiku-4-5-20251001

If you want to see it generate a Haiku from your webcam I just upgraded my silly little bring-your-own-key Haiku app to use the new model: https://tools.simonwillison.net/haiku

Wasn't there a 3.5 haiku too?

https://aws.amazon.com/about-aws/whats-new/2024/11/anthropic...

It's not a new product; just a new version.