Claude Haiku 5.5

Maker

Anthropic

Released

7 Oct 2026

Open weights

No, you use it through the maker's app or paid API

License

Owned by the maker, not open

Memory (context window)

1 million tokens (how much it can read at once)1,000,000 tokens exactly

Price

$0.1 for every million tokens you send, $0.5 for every million tokens it writesA token is a small piece of a word · checked 17 Oct 2026 · price source

Official page

Official page for Claude Haiku 5.5 (anthropic.com)

• All-roundArtificial Analysis Intelligence Index

  43 index points #9 of 17 models scored independent

  One combined score from many independent tests of how smart a model is.

  setting: max · as of 17 Oct 2026 · source

• Build websites & appsLMArena WebDev

  1585 Arena score #11 of 18 models scored independent

  When people ask two AIs to build the same website or app and compare the results, which one do they pick?

  setting: High · as of 17 Oct 2026 · source

• CodingLiveBench 2.0 Coding

  84.5 score out of 100 Tied #7 of 15 models scored independent

  Fresh coding tasks with tests that check the answer, changed often so models cannot memorize them.

  setting: highest supported effort · as of 14 Oct 2026 · source

• ReasoningLiveBench 2.0 Reasoning

  84.6 score out of 100 #8 of 15 models scored independent

  Fresh logic and puzzle questions with one right answer, changed often so models cannot memorize them.

  setting: highest supported effort · as of 14 Oct 2026 · source

• Science questionsGPQA Diamond

  85% #5 of 6 models scored maker's own number

  Very hard science questions in biology, chemistry and physics, written by PhD experts.

  as of 17 Oct 2026 · source

• Hardest examHumanity's Last Exam (no tools)

  45.9% #3 of 6 models scored maker's own number

  2,500 expert questions written to be too hard for AI, answered without web search or code.

  as of 7 Oct 2026 · source

• New puzzlesARC-AGI-2

  61.3% #7 of 11 models scored independent

  New picture puzzles a model has never seen, so it has to reason instead of remember. Harder for AI than for people.

  setting: XHigh, $0.085 per task · as of 18 Oct 2026 · source

• SpeedOutput speed

  235 tokens per second #2 of 16 models scored independent

  How many tokens (pieces of words) per second the model writes once it starts answering. Higher is faster.

  setting: max · as of 17 Oct 2026 · source

• Moonshot AIKimi K3Open weights. License: Kimi K3 license: free to use with conditions44 index points#8 of 17 models scored
• Z.aiGLM-5.3Open weights. License: GLM-5.3 license: free to use with conditions45 index points#7 of 17 models scored
• xAIGrok 4.746 index pointsTied #5 of 17 models scored

No stories about Claude Haiku 5.5 on ITG Now yet.

More from Anthropic

• Anthropic · 18 OctAnthropic puts 5% of its shares in a public fund
• Anthropic · 17 OctAnthropic signs first Canada data center deal
• Anthropic · 17 OctAnthropic quietly pitches its own AI safety bill
• Anthropic · 16 OctClaude solves a 25-year-old encryption mystery