Test CORS configuration. A must-have tool for API development and testing.
location /api/ {
add_header 'Access-Control-Allow-Origin' '*';
add_header 'Access-Control-Allow-Methods' 'GET, POST';
add_header 'Access-Control-Allow-Headers' 'Content-Type, Authorization';
add_header 'Access-Control-Max-Age' 86400;
}app.use((req, res, next) => {
res.header("Access-Control-Allow-Origin", "*");
res.header("Access-Control-Allow-Methods", "GET, POST");
res.header("Access-Control-Allow-Headers", "Content-Type, Authorization");
res.header("Access-Control-Max-Age", "86400");
if (req.method === "OPTIONS") return res.sendStatus(204);
next();
});Set up your API request or data.
Run or process the request.
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Use the CORS Tester when debugging cross-origin request failures, verifying CORS configuration after server changes, or planning CORS policies for new API deployments. It is essential for frontend developers encountering CORS errors and backend developers configuring cross-origin access for their APIs and microservices.
Yes, the CORS Tester is completely free with no testing limits or restrictions. Test CORS configurations for any number of endpoints and origins without premium requirements. All CORS headers and preflight scenarios are covered.
Yes, the CORS Tester sends actual preflight (OPTIONS) and cross-origin requests to your specified endpoints. It captures and analyzes the Access-Control-Allow-Origin, Access-Control-Allow-Methods, Access-Control-Allow-Headers, and other CORS response headers to verify your server's configuration.
The tester analyzes all standard CORS headers including Access-Control-Allow-Origin, Access-Control-Allow-Methods, Access-Control-Allow-Headers, Access-Control-Expose-Headers, Access-Control-Max-Age, and Access-Control-Allow-Credentials. It reports whether simple and preflight requests succeed from specified origins.