Claude Sonnet 5.5
Claude Sonnet 5.5 is Anthropic's Sonnet-class model for well-scoped everyday work, succeeding Claude Sonnet 5 as a direct upgrade.
Specifications
| Lab | Anthropic |
|---|---|
| Context window | 1M tokens |
| Input price | $2.00/1M |
| Output price | $10.00/1M |
| Release | Sep 2026 |
Strengths
- Direct upgrade over Sonnet 5 for well-scoped everyday work
- Strong at building features and fixing bugs in existing codebases
- 1M-token context window covers large multi-file tasks
- $2/$10 per M pricing, well below Opus-class flagships
Weaknesses
- Below Opus 5.5 on demanding reasoning and long-horizon agents
- Mid-tier positioning means heavier tasks still need Opus
Best for
- Everyday coding assistance and code review
- Bug fixing in large existing codebases
- Cost-aware agentic coding workflows
In Depth: Claude Sonnet 5.5
Summary
Claude Sonnet 5.5 is an AI model from Anthropic.
Released in Sep 2026. It takes text, image, and file input and produces text output, with a context window of 1M tokens. Input pricing is $2.00 per 1M tokens and output is $10.00 per 1M tokens on OpenRouter.