Using Opus 5.5 feels like hitting every green light on your drive home, drinking a cold glass of water when you're thirsty, and a hot shower after a long day. It's super smart, it writes clearly, it's fast, and it costs way less. It's a very good model.

Claude@claudeaiSep 22

Introducing Claude Opus 5.5, the first model in our new Claude 5.5 family. It performs at the level of Claude Fable 5.1 for most tasks, and costs 40% less to run than Opus 5.