Simon Willison’s Weblog

Subscribe

21st November 2025

Tool CORS Fetch Tester — Test HTTP requests directly in your browser and inspect the response headers and body that CORS restrictions allow you to access. This tool supports custom headers, request bodies in JSON or form-encoded formats, and includes a curl command importer for quickly setting up requests. The application uses shareable URL fragments to save your request configuration for later use.

Recent articles

This is a beat by Simon Willison, posted on 21st November 2025.

Monthly briefing

Sponsor me for $10/month and get a curated email digest of the month's most important LLM developments.

Pay me to send you less!

Sponsor & subscribe