Claude Sonnet 4.5
Key facts · verified Oct 29, 2026
Claude Sonnet 4.5 is an Anthropic model. Status: Deprecated - shutting down 30 November 2026; replacement: claude-sonnet-5-5. Its API price is $3 per million input tokens and $15 per million output tokens. Its context window is 200K tokens. It ranks #73 on LMArena's text leaderboard (Elo 1455, read 1 Nov 2026). Source: platform.claude.com.
Claude Sonnet 4.5 High 32K is the LMArena listing of Anthropic's Claude Sonnet 4.5 (claude-sonnet-4-5-20250929) with extended thinking. Anthropic deprecated the model on September 30, 2026 and will retire it on the Claude API on November 30, 2026, naming claude-sonnet-5-5 as the replacement. It is priced at $3 per million input tokens and $15 per million output tokens, with a 200K-token context window. 1455 Elo (rank 73)
Full Specifications
$3 / $15 per million tokens | |
|---|---|
| Identity | |
| Developer | Anthropic |
| Status | Deprecated - shutting down 30 November 2026; replacement: claude-sonnet-5-5 |
| Licence | Proprietary |
| Self-hostable | No |
| Cost | |
| Blended $/1M tokensinput × 0.75 + output × 0.25 | $6.000 / 1M tokens |
| Input price | $3.000 / 1M tokens |
| Output price | $15.000 / 1M tokens |
| Capacity | |
| Context window | 200K tokens |
| Measured quality | |
| LMArena Elo | 1455 (checked Nov 2026) |
| LMArena rank | Rank 73 |
| Elo per dollarLMArena Elo ÷ blended $/1M tokens | 243 |