CORS Tester

Use this little website to test if a URL is setup correctly to work with CORS.

Shareable link: https://cors-test.codehappy.dev/?method=get&origin=https%3A%2F%2Fcors-test.codehappy.dev%2F&url=https%3A%2F%2Fday.ag%2F.well-known%2Fnostr.json

Results

This URL will work correctly with CORS.

Headers

These are the response headers received when making the request.


  accept-ranges: bytes
access-control-allow-origin: *
alt-svc: h3=":443"; ma=2592000
cache-control: no-store, no-cache, must-revalidate
cf-cache-status: DYNAMIC
cf-ray: 9d7eb2841a18fad4-CMH
content-length: 258
content-type: application/json
date: Fri, 06 Mar 2026 04:43:04 GMT
etag: "dfr888qadbcx76"
last-modified: Sat, 17 Jan 2026 22:44:20 GMT
server: cloudflare
vary: Accept-Encoding

CORS tester was built by @mscccc. The code is available on GitHub. Sponsored by HTML/CSS to Image.