Anthropic confirmed the release of Claude Opus 5.5 on September 22, 2026, and announced that Sonnet 5.5 and Haiku 5.5 would follow. What it did not do is release those models.
Today, we’re excited to announce the availability of Claude Sonnet 5.5 on Amazon Bedrock and Claude Platform on AWS. Claude Sonnet 5.5 is a smarter, more efficient Sonnet model suited for focused coding and knowledge work with lower cost per task for most work at faster speed.
Anthropic released Claude Sonnet 5.5 on Monday, six days after launching Opus 5.5, and for most people the smaller model may turn out to be the more important release of the two.
As the AI model wars continue, Anthropic has released the newest version of Sonnet, the company’s mid-tier model, which it says will work much faster (and for significantly less) than its predecessor.
