Anthropic unveils Sonnet 5.5, claiming 30% faster performance and lower token consumption

Anthropic has released Claude Sonnet 5.5, the latest version of its mid-tier model, claiming it is 30 percent faster than its predecessor and consumes significantly fewer tokens. The company positions the model as an assistant for everyday tasks such as coding and creating office documents.

Sonnet 5, which launched in late June 2026, was initially pitched around efficient agentic deployment. Sonnet 5.5's key selling point is speed. Anthropic's benchmarks show Sonnet 5.5 outperforming the more powerful Opus 5.5 on agentic coding tasks, likely because it can spawn multiple agents without exceeding cost limits.

Anthropic also says Sonnet 5.5 has cyber capabilities comparable to Opus 5, making it the first Sonnet model subject to the same cyber safeguards applied to Fable and Opus. A new version of Haiku, its smallest model, is planned in the coming weeks, though no specific date was given.

The release comes as major AI labs continue to accelerate model launches. On September 22, 2026, OpenAI unveiled enhanced versions of its Sol and Luna models, and Meta announced a new model intended for a smart glasses feature.