Introducing Sonnet 4.6

Summary

Claude Sonnet 4.6 is introduced as an upgrade across coding, computer use, long-context reasoning, agent planning, knowledge work, and design. It adds a 1M token context window in beta, becomes the default for Free and Pro users in claude.ai and Claude Cowork, and keeps Sonnet 4.5’s starting price of $3/$15 per million tokens. Early testing reports that users preferred it over Sonnet 4.5 in Claude Code roughly 70% of the time and over Opus 4.5 59% of the time. The release also reports gains on OSWorld computer use, prompt-injection resistance, OfficeQA document comprehension, and long-horizon planning, while adding adaptive and extended thinking, beta context compaction, and generally available code execution, memory, programmatic tool calling, tool search, and tool-use examples.

Takeaways

1. 1

   Sonnet 4.6 matches Opus 4.6 performance on OfficeQA, which tests extracting and reasoning over facts in enterprise documents, including charts, PDFs, and tables.

2. 2

   In Vending-Bench Arena, Sonnet 4.6 invested heavily in capacity during the first ten simulated months before pivoting toward profitability, finishing well ahead of competitors.

3. 3

   The API’s web search and fetch tools can automatically write and execute code to filter search results, retaining relevant content to improve response quality and token efficiency.