Claude Sonnet 4.6: clean upgrade of 4.5, mostly better with some caveats

**Anthropic** launched **Claude Sonnet 4.6**, an upgrade over Sonnet 4.5, featuring broad improvements in **coding, long-context reasoning, agent planning, knowledge work, and design**, plus a **1M-token context window (beta)**. Benchmarks show Sonnet 4.6 leading on **GDPval-AA ELO 1633**, with significant token usage increases and improved output aesthetics. Integrations include **Cursor, Windsurf, Microsoft Foundry, and Perplexity Pro/Max**. Early user feedback noted some regression issues that were later fixed. Pricing remains the same as Sonnet 4.5. Tooling enhancements include code execution for filtering results, improving accuracy and efficiency.