Anthropic Unveils Claude Opus 4.6 with 1M Token Context Window

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Anthropic has released Claude Opus 4.6, delivering major upgrades to agentic coding, multi-step planning, and long-context retrieval with a 1M token beta window, alongside new effort controls at existing API pricing.

Key points

  1. First Opus-tier model with a 1M token context window, available in beta.
  2. Top scores across benchmarks including Terminal-Bench 2.0, Humanity's Last Exam, and GDPval-AA (+144 Elo over GPT-5.2).
  3. Significant reduction in context rot: scores 76% on the 1M 8-needle MRCR v2 benchmark compared to 18.5% for Sonnet 4.5.
  4. New capabilities: agent teams in Claude Code, API context compaction, adaptive thinking, and fine-grained effort controls.
  5. Product updates: major enhancements to Claude in Excel and the introduction of Claude in PowerPoint as a research preview.
  6. Pricing remains unchanged at $5 input and $25 output per million tokens.

Why it matters

Autonomous developer workflows and deep enterprise research often degraded as token counts mounted. With drastically improved long-context fidelity, multi-agent orchestration, and native tool chaining, Opus 4.6 makes complex, repository-scale work significantly more dependable.

Analysis

Anthropic focuses Opus 4.6 heavily on sustained agentic execution and context retention. The addition of effort parameters is a practical enhancement, giving developers direct control to reduce unnecessary latency and token costs on straightforward tasks where extensive reasoning is redundant.

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Summary generated by AI (Gemini 3.8 Flash, 27 September 2026). It may contain errors – the original source is authoritative.

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    7210 Mattersburg, Austria
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