Claude Sonnet 5.5
Near-flagship intelligence at a mid-tier price; the everyday workhorse for builders.
Claude Sonnet 5.5 is Anthropic’s Sonnet-class model for well-scoped everyday work, succeeding Claude Sonnet 5 as a direct upgrade. It is especially strong at building features, fixing bugs and producing polished documents.
- Provider
- Anthropic
- Type
- Language model
- Released
- Sep 28, 2026
- Context window
- 1M tokens
- Max output
- 128K tokens
- Price
- $2.00 input / $10.00 output per 1M tokens
- Input
- text, image, file
- Output
- text
- Open weights
- No
- Knowledge cutoff
- Jun 1, 2026
Best for
- Coding
- Agents
- Writing
- Chat & assistants
- Long context
- Enterprise
Strengths
- Best price-to-intelligence in the Claude line
- Fast for its class
- Agentic coding
More from Anthropic
- Claude Opus 5.5 — Anthropic. Anthropic’s flagship for demanding reasoning, coding and long-horizon agents.
- Claude Haiku 5.5 — Anthropic. Small, fast and inexpensive — built for subagents, summarization and browser use.
- Claude Fable 5.1 — Anthropic. Premium model for long-running agentic workflows, refactors and visual front-end work.
- Claude Opus 5 — Anthropic. Previous-generation Opus; still a strong reasoning and coding model.
Tools that use it
- Claude Code — Anthropic. Agentic coding in your terminal, IDE and browser.
- GitHub Copilot — GitHub (Microsoft). The most widely deployed AI pair programmer.
- Cursor — Anysphere. The AI-native code editor.
- Claude Agent SDK — Anthropic. The agent harness behind Claude Code, as a library.
- Amazon Bedrock — AWS. Foundation models on AWS.
- Claude — Anthropic. Anthropic’s AI assistant for thinking and making.