CORS Tester

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




If your CORS setup is not using a wildcard then this should be a domain that matches your AllowedOrigins


Shareable link:

Results

This URL will not work correctly with CORS.

What's wrong?

It does not have the access-control-allow-origin header set to *. Without this header, requests from other domains cannot be made to it via a users browser.

How to fix it?

If you have access to the server for the URL, you'll need to modify it to add the access-control-allow-origin header. If you do not have access, you'll need to upload the file somewhere else.

Headers

These are the response headers received when making the request.

cf-cache-status: BYPASS
content-type: text/html; charset=iso-8859-1
date: Mon, 26 Jan 2026 00:12:02 GMT
nel: {"report_to":"cf-nel","success_fraction":0.0,"max_age":604800}
report-to: {"group":"cf-nel","max_age":604800,"endpoints":[{"url":"https://a.nel.cloudflare.com/report/v4?s=nvuAm9Uhqa1LI1uL6RzLeK5vT56gVHp952WB3bjdfvzZ2lu2kwCqIJKCp5eXNr4oPMMzKz8JemKGhcDWTFfldwLai8bfE7yzWebQlfrbiDVYi9%2FVbNVk3o8%3D"}]}
server: cloudflare
transfer-encoding: chunked
vary: accept-encoding
  

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