[DetroitThrow]

It's mainly that people on here, regardless of profession, speak incorrectly but confidentally about things that could be easily verified with a Google search or basic familiarity with the thing in question.

Haiku 4.5 is a reasoning model, regardless of whatever hallucination you read. Being a hybrid reasoning model means that, depending on the complexity of the question and whether you explicitly enable reasoning (this is "extended thinking" in the API and other interfaces) when making a request to the LLM, it will emit reasoning tokens separately prior to the tokens used in the main response.

I love your theory that there was some mix up on their side because they were lazy and it was just some marketing dude being quirky with the technical language.

[CharlesW]

> It's mainly that people on here, regardless of profession, speak incorrectly but confidentally about things that could be easily verified with a Google search or basic familiarity with the thing in question.

Yep. And if your heart wants to call Haiku a "reasoning model", obviously you must listen. It doesn't meet that bar for me for a couple reasons: (1) It lacks both "adaptive thinking" and "interleaved thinking" (per Anthropic, both critical for reasoning models), and (2) it also performed unacceptably with a real-world collection of very basic reasoning tasks that I tried using it for.¹ I'm glad you're having better luck with it.

That said, it's a great and affordable little model for what it was designed for!

¹ I once made the mistake of converting a bunch of skills (which require basic reasoning) to use Haiku for Axiom (https://charleswiltgen.github.io/Axiom/). It failed miserably, and wow, did users let me have it. On the bright side, as a result I'm now far better at testing models' ability to reason.

[throwdbaaway]

We are all reasonable people here, and while you are (mostly) correct, I think we can all agree that Anthropic documentation sucks. If I have to infer from the doc:

* Haiku 4.5 by default doesn't think, i.e. it has a default thinking budget of 0.

* By setting a non-zero thinking budget, Haiku 4.5 can think. My guess is that Claude Code may set this differently for different tasks, e.g. thinking for Explore, no thinking for Compact.

* This hybrid thinking is different from the adaptive thinking introduced in Opus 4.6, which when enabled, can automatically adjust the thinking level based on task difficulty.