Check whether a target API allows cross-origin access from the browser perspective, with configuration advice
FAQ
What does a blocked result mean here?
It means the server is reachable, but the response lacks an Access-Control-Allow-Origin header for the current origin, so the browser hides the response from page scripts. It does not mean the server is down or misconfigured for sure.
Is the check request uploaded or logged?
When you run a check, the target URL is sent as a real HTTP request to the target server through your network, with headers such as the current page Origin. Results are shown on this page only and never stored or uploaded by this site.
All data is processed locally in your browser. Nothing is uploaded.