Claude API Dynamic Web Search Filtering: 11% Accuracy Gain + 24% Token Reduction + Free Code Execution

Anthropic Claude Blog·high signal

Anthropic's web search and web fetch tools now write and execute code to filter results before they reach the context window, improving Sonnet 4.6 from 33.3% to 46.6% and Opus 4.6 from 45.3% to 61.6% on BrowseComp and DeepsearchQA benchmarks. Ships via the web_search_20260209 tool version with anthropic-beta: code-execution-web-tools-2026-02-09 header; code execution is free when paired with web search or web fetch. Enables agents to discard irrelevant content programmatically before it consumes the context budget.