CORS Checker API — Test Cross-Origin Resource Sharing Policies
Check CORS (Cross-Origin Resource Sharing) headers for any URL. Verify if a resource allows cross-origin requests from your domain. Free API.
What is CORS Checking?
CORS checking tests whether a web resource allows cross-origin requests by sending a preflight OPTIONS request and inspecting the returned CORS headers. The API checks Access-Control-Allow-Origin, Access-Control-Allow-Methods, Access-Control-Allow-Headers, and other CORS-related headers.
How to Use It
Call GET /api/v1/cors-check?url=https://api.github.com. Returns { url: string, cors_enabled: boolean, allowed_origins: string, allowed_methods: string, allowed_headers: string, max_age: number | null, supports_credentials: boolean }.
Try it live
Test this endpoint in the interactive console
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Frequently Asked Questions
What is a CORS preflight request?
A preflight request is an OPTIONS request sent by the browser before the actual request to check if the server permits the cross-origin request.