Anthropic announced Claude Sonnet 4.6 on February 17, 2026, describing it as the company's most capable Sonnet model to date, with a full upgrade across coding, computer use, long-context reasoning, agent planning, knowledge work, and design. A 1M token context window is available in beta, and the model became the defa Pricing is unchanged from Sonnet 4.5 at $3 per million input tokens and $15 per million output tokens. Anthropic reports that early-access developers often preferred Sonnet 4.6 over its predecessor and even over the November 2025 Opus 4.5, and that major improvements in computer-use skills were measured on the OSWorld

The Opper AI release tracker independently corroborates that Claude Sonnet 4.6 was released by Anthropic on February 17, 2026, listing it with a 1M token context window, a listed price of $3/$15 per million tokens, and an Intelligence index score of 37. The same row sits between Claude Opus 4.6 (February 5, 2026) and C Because Opper AI aggregates every dated Anthropic launch, the page also contextualizes Sonnet 4.6 against later family releases such as Claude Sonnet 5 (June 30, 2026) and Claude Opus 5 (July 24, 2026), but no model-level technical detail beyond the release date, context size, and price is supplied for the Sonnet 4.6 r