CORS Tester

The CORS checker is a free tool by Corsfix that helps you to check whether a given URL supports cross origin requests or not. You can test any URL for free without registration.

Enter the URL you want to test and the origin making the request. Click on the 'Test' button to see if the request will succeed or be blocked by CORS. You can also adjust the request method, headers, and body.

The CORS tester works by simulating a CORS request to the given URL. Allowing you to test if the URL supports CORS or not, without having to test CORS using other application such as with Postman.

Origin is where the request is coming from. It is the domain of the website that is making the request. For example, if you are testing a request from https://example.com, then https://example.com is the origin.

Postman is a backend client that does not enforce the browser's Same-Origin Policy (SOP). Our CORS tester simulates a real browser environment, which is why it reveals security blocks that Postman ignores. If it fails here, it will fail for your users in Chrome, Firefox, or Safari.

Yes. When you test methods like POST, PUT, or DELETE, or add custom headers, browsers send an automated 'Preflight' OPTIONS request. This tool verifies if your server correctly handles these requests and returns the necessary Access-Control-Allow-Methods and Access-Control-Allow-Headers.

If your request includes credentials (Cookies), the CORS spec prohibits using a wildcard (*). In these cases, your server must specify the exact Origin and set 'Access-Control-Allow-Credentials: true' for the request to succeed.

Absolutely. You can set the 'Origin' field to http://localhost:3000 (or your specific port) to simulate how your local frontend will interact with a remote production API, allowing you to debug configuration issues before deployment.

Our tester performs a deep scan of all standard headers, including Access-Control-Allow-Origin, Access-Control-Expose-Headers, Access-Control-Max-Age, and Access-Control-Allow-Methods, ensuring your server configuration is fully compliant with modern browser security standards.

If you don't have access to the server's backend to change headers, the fastest solution is using a CORS Proxy like Corsfix. By routing your request through our proxy, the necessary headers are added automatically, allowing your frontend to access the resource instantly.

Corsfix is the CORS Proxy that lets you access any web resource without CORS errors. If you are trying to fetch a URL you don't own that doesn't support CORS, Corsfix can help you access that URL without getting CORS errors.