Check a server's CORS response headers for a URL and optional Origin, with a clear allowed/blocked verdict and fix hints.
Check the CORS policy of a URL for an optional Origin and return the Access-Control-* headers with a verdict and issues.
Easiest way: the APIHub CLI. Credits cover x402, no wallet needed.
# install and set up once
npx @apihubio/cli register
npx @apihubio/cli topup 10
# call this service
npx @apihubio/cli call -X GET "https://proxy.apihub.io/cors-checker/v1/check?url=https://example.com&origin=https://app.example.com"Or call the proxy directly (curl / any HTTP client):
curl https://proxy.apihub.io/cors-checker/v1/check?url=https://example.com&origin=https://app.example.com \
-H "Authorization: Bearer ahk_your_key"
# If credits available: charged automatically, returns 200
# Otherwise: returns 402 (pay via @x402/fetch or top up credits)Estimate your monthly cost for CORS Policy Checker.