Simon Willison’s Weblog

Subscribe

21st November 2025

Tool CORS Fetch Tester — Test HTTP requests directly from your browser and observe which response headers and body content are accessible under CORS (Cross-Origin Resource Sharing) restrictions. This tool lets you construct requests with custom methods, headers, and body content, import requests from curl commands, and format JSON responses for easier inspection. The application preserves your request configuration in the URL fragment, allowing you to share and bookmark specific test cases.
Posted 21st November 2025 at 5:37 am

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