Claude 4

May 28, 2025

Anthropic:

Claude Opus 4 is the world’s best coding model, with sustained performance on complex, long-running tasks and agent workflows. Claude Sonnet 4 is a significant upgrade to Claude Sonnet 3.7, delivering superior coding and reasoning while responding more precisely to your instructions.

The intro video “A day with Claude” is a cool picture of how some of the integrations work.

Claude Opus 4 also dramatically outperforms all previous models on memory capabilities. When developers build applications that provide Claude local file access, Opus 4 becomes skilled at creating and maintaining ‘memory files’ to store key information. This unlocks better long-term task awareness, coherence, and performance on agent tasks[.]

Simon Willison has an excellent writeup and analysis on the prompts and details of Claude 4.