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...
Anthropic: Claude Sonnet 5.5 — Anthropic. Context window 1,000,000 tokens. API pricing (per 1M tokens): Input $2, Output $10. License: Proprietary. LMArena 1,467. GPQA Diamond 95.6%.
| Provider | Anthropic |
|---|---|
| API model ID | anthropic/claude-sonnet-5.5 |
| Tier | Frontier |
| Context window | 1,000,000 tokens |
| Max output | 128,000 tokens |
| License | Proprietary |
| API pricing (per 1M tokens) · Input | $2 |
| API pricing (per 1M tokens) · Output | $10 |
| LMArena | 1,467 (claude-sonnet-5.5-xhigh) |
| GPQA Diamond | 95.6% |
LMArena (CC-BY 4.0, best reasoning setting, 2026-10-02) · GPQA Diamond: Epoch AI (CC-BY 4.0)
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