Claude Opus 5.5
ModelActiveby Anthropic · family “claude-opus”
Claude Opus 5.5 is Anthropic's flagship model for demanding reasoning, coding, and long-horizon agentic work, succeeding Claude Opus 5. It is particularly strong at multi-step changes in large codebases, code... (description from the OpenRouter listing)
in: textin: imagein: fileout: textReasoningTool useStructured output
Epoch Capabilities Index
Not scored by Epoch AI
Released
22 Sep 2026
Context window
1M tokens
Max output
128K tokens
Input $ / 1M tokens
$4.00
Output $ / 1M tokens
$20.0
Cached input $ / 1M
$0.20
Each benchmark shown separately with its own source
Benchmark results (8)
| Benchmark | Domain | Score | vs best recorded | Setting | Run | Source |
|---|---|---|---|---|---|---|
| Furniture Assembly | multimodal | 83.3% ±4.7 | 100% | max | 22 Sep 2026 | Epoch ↗ |
| LMCA | agents | 68.2% | 100% | max | — | External ↗ |
| DTBench | reasoning | 98.9% | 100% | max | — | External ↗ |
| EBR-bench | reasoning | 71.4% ±7.1 | 94% | max | 22 Sep 2026 | Epoch ↗ |
| ProofBench | math | 100.0% | 100% | max | — | External ↗ |
| APEX-Agents | agents | 73.5% | 97% | max | — | External ↗ |
| ARC-AGI-2 | reasoning | 91.7% | 96% | max | — | External ↗ |
| ARC-AGI | reasoning | 97.5% | 99% | max | — | 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
Unchanged since first recorded on 27 Sep 2026 (OpenRouter listing); re-read on every data refresh, most recently 9h ago. Steps show when the price changed.
Events
- Model launchMajorAnthropic releases Claude Opus 5.5OpenRouter models API
- BenchmarkEpoch AI evaluates Claude Opus 5.5Epoch AI Benchmarking Hub