Claude Haiku 5.5, the Anthropic model in numbers

What you need to know

Anthropic released Claude Haiku 5.5 on October 7, 2026. It has a reasoning mode: it can "think" before answering, which helps with multi-step problems but uses more tokens, and therefore more money. It is a closed model: you access it through an API, from Anthropic or one of the 34 providers listed on models.dev. It is a very recent release.

We file it under frontier models (24 models in this category on the site).

What do independent benchmarks say?

According to results published by Epoch AI (checked on October 22, 2026), Claude Haiku 5.5 has a capability index of 84 out of 100, computed on 5 benchmarks from our basket.

That puts it at #20 in our weekly model ranking.

• GPQA Diamond (PhD-level science questions): 89.6% — the best tracked model, Gemini 4 Argon, reaches 96.4%
• OTIS Mock AIME (competition mathematics problems): 98.9% — the best tracked model, GPT-5.5 Pro, reaches 100%
• FrontierMath (very hard research-level mathematics): 75.1% — the best tracked model, GPT-6 Astra, reaches 93.7%
• FrontierCode (advanced programming tasks): 46.4% — the best tracked model, Claude Opus 5.5, reaches 54.6%

Technical specifications

Its context window reaches 1,000,000 tokens, roughly 1,500 pages of text at 500 words per page: enough to load a whole book or a mid-sized codebase. A single answer can run to 128,000 tokens.

It accepts as input: text, image and PDF. Its knowledge stops at June 2026: beyond that, it needs web search or your documents.

It can call tools (functions, APIs) and return structured JSON output, which makes it a possible foundation for an AI agent.

Pricing and budget

Claude Haiku 5.5 costs $0.10 per million input tokens and $0.50 per million output tokens (developer's price, checked on October 22, 2026).

To put it in perspective: reading 20,000 tokens (about thirty pages) and writing 2,000 costs roughly $0.003; a thousand of those tasks, $3.

That is 29 times cheaper than the median output price of frontier models ($14.5).

Tokens read back from cache cost $0.01 per million, which helps an agent that keeps resending the same context.

To estimate your own budget, use the agent cost calculator.

Who is it for?

Given its category, Claude Haiku 5.5 is mainly aimed at hard tasks where quality matters more than cost: deep reasoning, complex code, long analyses.

Its FrontierCode result (46.4%, above the median of tracked models) makes it a serious candidate for coding agents.

Its very large context window makes it worth considering for analysing large sets of documents in a single request.

Its very low cost (under half a cent for our sample task) means it can be called thousands of times a day.

Before adopting it, test it on your own examples: benchmarks measure standard tasks, not your job.

Alternatives

In the same category, the models closest to Claude Haiku 5.5 are:

• GPT-5.2 (OpenAI, index 83.9)
• GPT-5.6 Terra (OpenAI, index 85.7)
• Gemini 3.7 Flash (Google DeepMind, index 85.9)
• Grok 4.6 (xAI, index 86.1)