Anthropic released Claude Sonnet 4.6 on February 17, 2026, positioning it as “our most capable Sonnet model yet” with upgrades across coding, computer use, long-context reasoning, agent planning, knowledge work, and design. The model features a 1M token context window in beta and is now the default model for Free and Pro plan users on claude.ai and Claude Cowork.
The release comes sixteen months after Anthropic first introduced computer use capabilities in October 2024. At that time, the company described the feature as “still experimental—at times cumbersome and error-prone,” but expected rapid improvement.
Sonnet 4.6 demonstrates significant advances on OSWorld, the standard benchmark for AI computer use that presents hundreds of tasks across real software including Chrome, LibreOffice, and VS Code running on simulated computers. The model interacts with computers using virtual mouse clicks and keyboard input without special APIs or purpose-built connectors. Early users report “human-level capability in tasks like navigating a complex spreadsheet or filling out a multi-step web form, before pulling it all together across multiple browser tabs.”
Developers with early access prefer Sonnet 4.6 over its predecessor “by a wide margin” and “often even prefer it to our smartest model from November 2025, Claude Opus 4.5.” The model delivers “performance that would have previously required reaching for an Opus-class model—including on real-world, economically valuable office tasks.” Pricing remains unchanged from Sonnet 4.5 at $3/$15 per million tokens.
Anthropic’s safety researchers concluded that Sonnet 4.6 has “a broadly warm, honest, prosocial, and at times funny character, very strong safety behaviors, and no signs of major concerns around high-stakes forms of misalignment.” The company notes improved resistance to prompt injection attacks compared to Sonnet 4.5, performing similarly to Opus 4.6 in safety evaluations.
