Claude Haiku 5.5

LLM
Anthropic
New

Claude Haiku 5.5 is designed for high-volume, cost-sensitive tasks like summaries, classification, and database queries.

Context tokens

1,000,000

Output tokens

128,000

Training cutoff

Jun 30, 2026

Released

Oct 7, 2026

Schema

Uses adaptive thinking at medium effort by default; you can raise or lower the effort level to trade off speed and cost against response quality.

Schema documentation

Capabilities

Tool use
Structured output
Thinking
Effort: low · medium · high · xhigh · max
Multilingual
Multimodal

Supported languages

ar
cs
da
de
el
en
es
fi
fr
hi
id
it
ja
ko
nl
pl
pt
ru
sv
zh

Supported input media

image
text

Supported tools

  • Seclai Content Tools

    Inspect source documents connected to your account. Includes tools for loading full content, reading character ranges, searching within documents, viewing stats, and listing available content sources. When a source_connection_content_version_id is provided in agent run metadata it is used as the default. Otherwise the model can discover content via list_content_sources.

  • Seclai Knowledge Base

    Search your knowledge bases using semantic similarity. Includes search_knowledge_base and list_knowledge_bases. When a knowledge_base_id is provided in the prompt or agent run metadata it is used as the default. Otherwise the model can discover available knowledge bases at runtime.

  • Seclai Memory Banks

    Manage persistent memory across agent runs. Includes tools for listing memory banks, writing entries, searching memory via semantic similarity, and loading entries in chronological order. Supports two memory types: 'conversation' (speaker-attributed turns) and 'general' (freeform text). Use key to organize entries by topic, session, or user.

  • Seclai Web Tools

    Fetch web pages and search the web from within agent prompt calls. Includes seclai_web_fetch for retrieving page content in markdown, HTML, or plain text, and seclai_web_search for finding relevant pages with content snippets.

  • Web Fetch

    The web fetch tool allows Claude to retrieve full content from specified web pages and PDF documents.

  • Web Search

    The web search tool gives Claude direct access to real-time web content, allowing it to answer questions with up-to-date information beyond its knowledge cutoff. Claude automatically cites sources from search results as part of its answer.

Variants

Context Window

Support for longer context windows.

OptionDescriptionInput credits (per 1k tokens)Output credits (per 1k tokens)Cache write (1h) credits (per 1k tokens)Cache write (5m) credits (per 1k tokens)Cache hit credits (per 1k tokens)
Less than 100K ContextContext windows of 100,000 tokens or fewer.1.336.652.661.66250.133
100K or More ContextContext windows larger than 100,000 tokens.6.6533.2513.308.31250.665

Try This Model

Write a prompt and experiment with Claude Haiku 5.5 in the model experiments page. You can compare it with other models side by side.