Anthropic has released Claude Sonnet 5, its most capable Sonnet model yet, narrowing the performance gap with the company’s more expensive Opus models across coding, reasoning and autonomous tool use.
The model can plan complex tasks, operate browsers and terminals, and continue working through multi step assignments with less user intervention than Claude Sonnet 4.6.
Anthropic said its performance is close to Claude Opus 4.8 in several agentic workloads, though Opus remains the stronger option when users prioritize accuracy over cost.
Sonnet 5 showed improvements over its predecessor on BrowseComp, an evaluation of agentic web research, and OSWorld Verified, which measures a model’s ability to complete tasks across computer interfaces. Anthropic said developers can adjust the model’s effort level to balance accuracy, speed and computing costs.
The model supports a one million token context window and up to 128,000 output tokens through the standard API. It is available under the API identifier claude-sonnet-5 through Anthropic’s platform, Amazon Bedrock, Google Cloud and Microsoft Foundry.
