Anthropic released Claude Opus 4.1 as a drop-in replacement for Opus 4, keeping the same pricing and rate limits. The upgrade focused on coding precision, multi-file refactors, and agentic task completion.

Anthropic positioned 4.1 as a refinement rather than a reinvention: better at following complex instructions and producing working code on the first pass. Benchmarks showed gains on agentic coding and tool-use evaluations.

The release continued Anthropic's mid-generation refresh pattern, squeezing more capability out of the Claude 4 architecture before the next numbered leap.