What changed: Anthropic released Claude Sonnet 5.5 on September 28. The company positions it as the faster, lower-cost option for everyday coding, bug fixes, documents, slides, and spreadsheets, while reserving Opus 5.5 for more open-ended work.
Anthropic says the model is priced the same as Sonnet 5—$2 per million input tokens and $10 per million output tokens—but typically needs fewer tokens per task. It also says output generation is more than 30% faster than the prior Sonnet model.
Why it matters: Teams using Sonnet for high-volume implementation work may be able to improve turnaround time without changing their basic cost tier. Anthropic is also shipping the model with cyber safeguards and fallbacks more like those used for its higher-capability models, a reminder that deployment controls are becoming part of routine model upgrades.