Anthropic Releases Claude Sonnet 4.6 with Improved Coding, Computer Use, and 1M Token Context Window

Claude Sonnet 4.6 Released

Anthropic has officially launched Claude Sonnet 4.6, its most capable mid-tier model to date, delivering a comprehensive upgrade across coding, computer use, long-context reasoning, agent planning, knowledge work, and design, all at the same price point as its predecessor.

The model is now the default on Free and Pro plans at claude.ai and Claude Cowork, with API pricing unchanged at $3/$15 per million input/output tokens.

Notably, Sonnet 4.6 ships with a 1 million token context window in beta, large enough to hold entire codebases, lengthy legal contracts, or dozens of research papers in a single request.

Coding Performance Enhancement

In developer testing, users preferred Sonnet 4.6 over Sonnet 4.5 approximately 70% of the time in Claude Code sessions, citing better context comprehension and reduced code duplication.

More remarkably, users preferred Sonnet 4.6 over Opus 4.5 Anthropic’s frontier model from November 2025, 59% of the time, rating it significantly less prone to overengineering, fewer hallucinations, and more consistent follow-through on multi-step tasks.

On the SWE-bench Verified benchmark, Sonnet 4.6 scores 79.6%, up from Sonnet 4.5’s 77.2%, approaching Opus 4.6’s 80.8%, making it the smallest performance gap between Sonnet and Opus tiers in any Claude generation.

Customers also reported that frontend code and financial analysis saw standout improvements, with visual outputs described as noticeably more polished, featuring better layouts, animations, and design sensibility, and requiring fewer iterations to reach production quality.

Computer Use Sees a Dramatic Leap

Sonnet 4.6 scores 72.5% on OSWorld-Verified Anthropic’s benchmark for autonomous computer use across real software, including Chrome, LibreOffice, and VS Code, nearly matching Opus 4.6 at 72.7% and nearly doubling GPT-5.2’s 38.2%.

This marks a staggering rise from 14.9% when computer use was first introduced in October 2024, representing roughly a 5× improvement across sixteen months.

Early users report human-level capability in tasks such as navigating complex spreadsheets and completing multi-step web forms across multiple browser tabs. Anthropic has also improved the model’s resistance to prompt injection attacks, a key security concern in agentic workflows, with Sonnet 4.6 performing comparably to Opus 4.6 on safety evaluations.

Platform Updates and Availability

On the Claude Developer Platform, Sonnet 4.6 supports adaptive thinking, extended thinking, and context compaction in beta, automatically summarizing older context as conversations approach limits.

Web search and fetch tools now automatically filter and process results via dynamic code execution, improving both response quality and token efficiency.

The Claude in Excel add-in now supports MCP connectors for integration with platforms including S&P Global, LSEG, PitchBook, Moody’s, and FactSet, available on Pro, Max, Team, and Enterprise plans.

Claude Sonnet 4.6 is available now on all Claude plans, Claude Code, the API, and major cloud platforms, including Microsoft Azure AI Foundry. Developers can access it via the API using the model string claude-sonnet-4-6.

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Guru Baran

Gurubaran KS is a cybersecurity analyst, and Journalist with a strong focus on emerging threats and digital defense strategies. He is the Co-Founder and Editor-in-Chief of Cyber Security News, where he leads editorial coverage on global cybersecurity developments.