Claude Opus 4.6: Anthropic’s Most Capable Model Yet
Published February 6, 2026 — 8 min read
On February 5, 2026, Anthropic released Claude Opus 4.6 — its most powerful AI model to date. Arriving just three months after Opus 4.5, this update delivers a massive expansion to the context window, a new “agent teams” paradigm for parallel task execution, and benchmark scores that surpass both OpenAI’s GPT-5.2 and Google’s Gemini 3 Pro across a range of evaluations.
Whether you’re a developer building agentic workflows, a knowledge worker producing professional documents, or a researcher wrestling with enormous datasets, Opus 4.6 marks a tangible leap in what an AI model can handle in a single session.
What’s New in Opus 4.6
While the version bump from 4.5 to 4.6 may seem incremental, the changes under the hood are substantial. Anthropic has focused on three pillars: reasoning depth, context capacity, and agentic execution.
A 5× increase over the previous 200K limit. Opus 4.6 scores 76% on the MRCR v2 needle-in-a-haystack benchmark at 1M tokens, compared to just 18.5% for Sonnet 4.5 — a qualitative shift in usable context.
Multiple specialised agents can now split a task and work in parallel — one on the frontend, one on the API, one on a migration — coordinating autonomously. Anthropic reports a roughly 30% reduction in end-to-end task runtime.
Replaces the binary on/off extended thinking toggle. Opus 4.6 dynamically decides how much reasoning effort a prompt requires. Four effort levels (low, medium, high, max) give developers fine-grained cost–speed–quality control.
A new beta feature that automatically summarises older context as conversations grow, enabling effectively infinite sessions without manual truncation or sliding-window hacks.
Claude now operates as a side panel inside PowerPoint, respecting your slide masters and layouts. Excel gets unstructured data support and longer workflows for paid subscribers.
Benchmark Breakdown
Opus 4.6 sets new state-of-the-art scores on several major evaluations. The most striking result is on ARC AGI 2, a benchmark designed to measure novel problem-solving that is easy for humans but notoriously hard for AI. Opus 4.6 scored 68.8% — nearly double Opus 4.5’s 37.6% and well ahead of GPT-5.2 (54.2%) and Gemini 3 Pro (45.1%).
| Benchmark | Opus 4.6 | Opus 4.5 | GPT-5.2 | Gemini 3 Pro |
|---|---|---|---|---|
| Terminal Bench 2.0 | 65.4% | 59.8% | — | — |
| OSWorld (Agentic) | 72.7% | 66.3% | < 72.7% | < 72.7% |
| ARC AGI 2 | 68.8% | 37.6% | 54.2% | 45.1% |
| MRCR v2 (1M ctx) | 76% | — | — | — |
| Humanity’s Last Exam | #1 | — | — | — |
Beyond the headline numbers, Opus 4.6 also tops the GDPval-AA benchmark for economically valuable knowledge work, outperforming GPT-5.2 by approximately 144 ELO points. In life sciences, it delivers nearly twice the performance of its predecessor on computational biology, structural biology, organic chemistry, and phylogenetics tests.
Coding and Developer Impact
Coding has always been a strength of the Opus line, and 4.6 takes it further. The model plans more carefully before generating code, catches its own mistakes through improved self-review, and sustains agentic tasks for longer without losing coherence. For large codebases, Anthropic claims it can now handle autonomous code review, debugging, and refactoring across repositories that would have previously required human intervention.
“Opus 4.6 is a model that makes the shift from chatbot to genuine work partner really concrete for our users.” — Scott White, Head of Product, Anthropic
The new agent teams feature in Claude Code is particularly noteworthy. Rather than a single agent working sequentially, developers can now spin up parallel agents that own distinct parts of a task. Anthropic’s example: one agent handles the frontend, another the API layer, and a third manages database migrations — all coordinating autonomously. This is available as a research preview and represents a meaningful step towards multi-agent orchestration out of the box.
Enterprise and Knowledge Work
Anthropic has been explicit about targeting enterprise workflows with this release. Roughly 80% of the company’s business comes from enterprise customers, and Opus 4.6 is tuned for the kind of work they care about: financial analysis, legal research, document production, and multi-step research tasks.
The model now leads on the Finance Agent benchmark and TaxEval by Vals AI. Combined with the expanded context window, analysts can feed entire filings, market reports, and internal data into a single session and get coherent, cross-referenced outputs. Anthropic says Opus 4.6 produces documents, spreadsheets, and presentations that approach expert-created quality on the first pass, reducing the rework cycle significantly.
Availability and API Changes
Opus 4.6 is live now across all major platforms. The API model identifier is simply claude-opus-4-6 — note the simplified naming without a date suffix. It’s available on the Anthropic API, AWS Bedrock, Google Vertex AI, Microsoft Foundry, and through GitHub Copilot for Pro, Pro+, Business, and Enterprise users.
Developers should be aware of a few breaking changes: assistant message prefilling now returns a 400 error (migrate to structured outputs or system prompt instructions), the output_format parameter has moved to output_config.format, and the effort parameter is now generally available without a beta header.
Safety and Alignment
Anthropic reports that the intelligence gains in Opus 4.6 have not come at the cost of safety. On their automated behavioural audit, the model showed low rates of misaligned behaviours including deception, sycophancy, and encouragement of user delusions — matching Opus 4.5’s results. Six new cybersecurity probes have been added to evaluate potential misuse vectors, and the model achieves a lower rate of unnecessary refusals compared to previous releases.
The Bigger Picture
Opus 4.6 arrives at a moment of intensifying competition. OpenAI announced its new OpenAI Frontier enterprise platform just hours before Anthropic’s launch, signalling a strategic pivot towards infrastructure and agent management rather than competing purely on benchmark scores. Google’s Gemini 3 Pro and Microsoft’s deep integration of Opus 4.6 into Foundry add further complexity to the landscape.
What sets this release apart is the combination of raw capability and practical utility. The 1M context window, agent teams, adaptive thinking, and context compaction aren’t just benchmark optimisations — they address real friction points that developers and knowledge workers hit daily. If Opus 4.5 moved Claude from “chatbot” to “useful tool,” Opus 4.6 positions it as a genuine work partner that can own entire workflows end-to-end.
For those already running Opus 4.5 in production, the upgrade path is a single API version change at the same price point. For everyone else, this is a strong argument to take a serious look at what Claude can do in 2026.
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