Sonnet 5.5 has the same feel I liked about Opus 5.5. It writes clearly, it's very fast, and it's a major capabilities jump over Sonnet 5. Really great model to iterate with.
Introducing Claude Sonnet 5.5, the second model in the Claude 5.5 family.
It’s a clear upgrade over Sonnet 5, runs more than 30% faster, and costs up to 30% less for most work.