Claude Sonnet 4.5 (1k thinking)
ModelActiveby Anthropic · family “claude-sonnetk-thinking”
Epoch Capabilities Index
Not scored by Epoch AI
Released
29 Sep 2025
Context window
Unknown
Max output
Unknown
Input $ / 1M tokens
Unknown
Output $ / 1M tokens
Unknown
Cached input $ / 1M
Unknown
Each benchmark shown separately with its own source
Benchmark results (2)
| Benchmark | Domain | Score | vs best recorded | Setting | Run | Source |
|---|---|---|---|---|---|---|
| ARC-AGI-2 | reasoning | 5.8% | 6% | 1K | — | External ↗ |
| ARC-AGI | reasoning | 31.0% | 31% | 1K | — | External ↗ |
Source: Epoch AI Benchmarking Hub (CC BY 4.0). “External” rows are leaderboard results Epoch collects from third parties. Best reported setting per benchmark is shown.
API list price over time
Price history
$ per 1M tokens
This model has no public API price listing
0 recorded prices on — (OpenRouter listing); re-read on every data refresh, most recently 10h ago. Steps show when the price changed.
Events
- Model launchMajorAnthropic releases Claude Sonnet 4.5 (1k thinking)Epoch AI Benchmarking Hub