| Item | Claude Opus 4.6 (public specs) |
|---|---|
| Model family | Claude Opus (Opus 4.6) |
| Model id | claude-opus-4-6 |
| Provider | Anthropic |
| Input types | Text, structured files (documents, spreadsheets), vision inputs (images/screenshots) — via Messages API and Files API |
| Output types | Text (long-form, code, structured outputs), streamed messages; supports document and structured outputs |
| Context window | 1,000,000 tokens (beta); compaction available to extend effective context |
| Max output tokens | 128,000 |
| Effort / reasoning controls | low, medium, high (default), max; plus adaptive thinking to let the model pick extended reasoning when useful |
| Long-context features | Context compaction (beta) with header compact-2026-01-12; streaming recommended for large outputs |
What is Claude Opus 4.6
Claude Opus 4.6 is Anthropic’s most capable Opus-class model (released Feb 5, 2026), tuned for complex, long-horizon knowledge-work and agentic coding workflows. It emphasizes reliable planning, sustained multi-step execution, and robustness on large codebases and enterprise tasks such as financial analysis, legal reasoning, and multi-document research.
Main features of Claude Opus 4.6
- Ultra-long context (beta): Support for a 1,000,000-token context window (beta) and server-side context compaction to summarize and preserve long-running conversational state.
- Very large outputs: Up to 128k output tokens, enabling single-request generation of large documents, reports, or multi-file code patches.
- Agentic workflows & agent teams: Research-preview support in Claude Code for spinning up multiple agents that coordinate in parallel for review, testing, and multi-step engineering tasks.
- Effort & adaptive thinking controls: Four effort levels (low/medium/high/max) and adaptive thinking that lets the model selectively apply extended reasoning when appropriate.
- Improved coding and tool use: Upgrades for code review, debugging, terminal-style agent workflows, and integrations with office tools (Claude in Excel / PowerPoint).
- Context compaction & long-run tooling: Server-side compaction strategy and SDK support (streaming) to manage long-running agents without manual state pruning.
Benchmark performance of Claude Opus 4.6
Anthropic reports leading performance on multiple evaluations: highest scores on Terminal-Bench 2.0 (agentic coding), top industry result on DeepSearchQA, a 144 Elo advantage over OpenAI’s GPT-5.2 on GDPval-AA, and a BigLaw Bench score of 90.2% (per Anthropic’s release and system card). See official system card and release notes for methodology and caveats.
| Benchmark / task | Opus 4.6 reported result (Anthropic) |
|---|---|
| Terminal-Bench 2.0 (coding) | 65.4% (industry-leading per Anthropic). |
| OSWorld (computer-using tasks) | 72.7% (Anthropic’s best computer-using model). |
| GDPVal / Elo (adaptive thinking, partner benchmarks) | Anthropic / partner prelaunch results report high Elo relative to other frontier models (vendor materials show Opus 4.6 leading on several agentic and coding benchmarks). Independent press summaries note Opus 4.6 outperforming GPT-5.2 on specific professional evaluations. |
Note: Benchmarks and reported comparisons are Anthropic’s published results from the Feb 5, 2026 announcement and system card; users should consult the system card for test methodology and dataset details.
Claude Opus 4.6 vs Opus 4.5 vs GPT-5.2 (comparative snapshot)
| Model | Strengths | Notes |
|---|---|---|
| Claude Opus 4.6 | Best-in-class long-horizon reasoning, agentic coding, 1M-token beta, 128k outputs | Anthropic reports gains over Opus 4.5 and OpenAI GPT-5.2 on GDPval-AA and Terminal-Bench. |
| Claude Opus 4.5 | Strong coding and agentic capabilities (previous baseline) | 4.6 improves planning and long-run stability. |
| OpenAI GPT-5.2 (reference) | Strong multimodal reasoning and broad deployment | Anthropic cites a ~144 Elo gap (GDPval-AA) in favor of Opus 4.6; comparisons vary by task and benchmark. |
Representative enterprise use cases
- Repository-scale code refactors, multi-file migrations, and automated patch generation.
- Long-running agentic workflows: automated research, multi-document synthesis, and CI orchestration.
- Financial analysis and legal research that require multi-source cross-checking and structured outputs.
- Document → slide workflows: ingest large spreadsheets, synthesize findings, and generate brand-consistent PowerPoint decks.
- Defensive security workflows: triage and reproduce vulnerabilities under controlled, audited conditions.
How to access and use Claude Opus 4.6 API
Step 1: Sign Up for API Key
Log in to cometapi.com. If you are not our user yet, please register first. Sign into your CometAPI console. Get the access credential API key of the interface. Click “Add Token” at the API token in the personal center, get the token key: sk-xxxxx and submit.
Step 2: Send Requests to claude-opus-4-6 API
Select the “claude-opus-4-6” endpoint to send the API request and set the request body. The request method and request body are obtained from our website API doc. Our website also provides Apifox test for your convenience. Replace <YOUR_API_KEY> with your actual CometAPI key from your account. Where to call it: Anthropic Messages format and Chat format.
Insert your question or request into the content field—this is what the model will respond to . Process the API response to get the generated answer.
Step 3: Retrieve and Verify Results
Process the API response to get the generated answer. After processing, the API responds with the task status and output data.