Claude Opus 4.6
Claude Opus 4.6 by Anthropic: 1M token context, adaptive thinking, effort controls, and context compaction for long-horizon agentic coding and search.
Model Overview
Capabilities, design details, and architectural traits
Claude Opus 4.6 - Overview
Claude Opus 4.6 is the Opus generation that introduced three capabilities new to the Opus class simultaneously: adaptive thinking, effort controls, and a 1M token context window in beta. These were not incremental updates to existing features - they each debuted with Opus 4.6. The model is designed around sustained, long-horizon agentic work.
| Trait | What it means for Opus 4.6 specifically |
|---|---|
| Adaptive thinking - first Opus deployment | thinking: {type: "adaptive"} was introduced with Opus 4.6; prior Opus models only had binary extended thinking on/off |
| Effort controls - four levels | low, medium, high (default), and max effort levels debuted here |
| 1M token context - first Opus | Beta 1M token context window arrived with Opus 4.6; previous Opus models topped at 200k |
| Context compaction - first general availability | Automatic context summarization near window limits launched alongside Opus 4.6 on the API |
| ASL-3 deployment with published Sabotage Risk Report | Opus 4.6 is the first model for which Anthropic committed to and published a formal Sabotage Risk Report under its Responsible Scaling Policy, separate from the system card |
| Agent teams in Claude Code - debut | The ability to assemble multi-agent teams within Claude Code launched with Opus 4.6 |
The ASL-3 Threshold and Sabotage Risk Report
Anthropic supplemented the Opus 4.6 system card with a dedicated Sabotage Risk Report - a formal safety artifact now required for all future models exceeding Opus 4.5's capability level under the Responsible Scaling Policy.
Benchmark Performance
Independent evaluations · Artificial Analysis
Accuracy & Capability Details
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| Model Details | |||
|---|---|---|---|
| General Info | |||
| Provider | Anthropic | Anthropic | Anthropic |
| Release Date | February 5, 2026 | September 22, 2026 | September 28, 2026 |
| Knowledge Cutoff | - | - | Jun 2026 |
| Context & Limits | |||
| Context Window | 1M | 1M | 1M |
| Pricing (per 1M tokens) | |||
| Input Pricing | $5 | $4 | $2 Best Input Pricing |
| Output Pricing | $25 | $20 | $10 Best Output Pricing |
| Modalities | |||
| Inputs | textimagefile | textimagefile | textimagefile |
| Outputs | text | text | text |
| Benchmarks (0-100) | |||
| Intelligence Index | 31.9 | 57.6 Best Intelligence Index | 56.0 |
| Coding Index | - | - | - |
| Agentic Index | - | - | - |
Humanity's Last Exam
Extremely difficult logical reasoning and knowledge.
Long Context Reasoning
Logical reasoning over long context windows.
SciCode Benchmark
Scientific coding and mathematical modeling.
Independent evaluation data provided by Artificial Analysis. To view the latest benchmarks and full details, visit their official site.
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