Claude Sonnet 5.5 is out: faster, and up to 30% cheaper

What happened?

On 28 September 2026 Anthropic released Claude Sonnet 5.5, the everyday model in its Claude 5.5 family. It arrived less than a week after Claude Opus 5.5. Reported details:

• More than 30% faster than the previous Sonnet.
• Described as strongest at well-scoped everyday tasks, fixing bugs, and creating polished documents, slides and spreadsheets.
• API pricing of $2 per million input tokens and $10 per million output tokens, with cached reads at $0.20 per million. Overall cost is up to about 30% lower for most work.
• Available in Claude for free and paid users, and through AWS, Google Cloud and Microsoft Azure.

Why does it matter?

Sonnet is the model most people end up using day to day: quick enough for normal chat, capable enough for real work. A faster, cheaper Sonnet usually means better free-plan experiences and cheaper AI-powered apps.

Who does it affect?

Everyday Claude users, and developers who build on Claude. Anthropic has also said a smaller Haiku 5.5, aimed at high-volume, low-cost uses, is expected in the coming weeks.

Can I use it now?

Yes, according to the reporting: it is available to both free and paid users.

How do I try it?

Open claude.ai and check the model picker. New to Claude? Start with What Is AI? and grab a prompt from the prompt vault.