Anthropic releases Claude Sonnet 4.6 with 1M-token context in beta

Anthropic released Claude Sonnet 4.6 on February 17. It broadens the family's reach across coding, computer use, long-context reasoning, agent planning, knowledge work and design. Sonnet 4.6 introduced a 1M-token context window in beta, a clear sign Claude was being tuned for large, messy work. Against Opus 4.6 released the same month, Sonnet 4.6 scores higher on real-world office benchmarks, making it the practical middle ground.