CORS checker
Sends a real request with an Origin header and checks the response for Access-Control-Allow-Origin and related headers. This checks a simple GET, not a full CORS preflight (OPTIONS) — some APIs only respond correctly to a real preflight.
What is CORS checker?
Cross-Origin Resource Sharing (CORS) headers determine whether a browser will let JavaScript running on one site fetch data from a different site — a frequent source of "blocked by CORS policy" errors when an API isn't configured to allow the origin making the request.
How to use it
Enter the URL to test and the origin you want to check — the tool sends a real request with that Origin header and reports whether the response headers actually permit it.
Example
Testing https://api.example.com with origin https://example.com might show:
Access-Control-Allow-Origin: https://example.com -> Allowed: Yes