cors-header-checker.underscoredone.com

answering

Sends a real request to any URL you provide, attaches an Origin header, and reads back all six standard cross-origin permission headers the server returns. Tells you whether cross-origin requests are enabled at all, whether your specific origin is permitted, and shows every permission value exactly as the server sent it. Useful for finding why a browser is blocking a request, confirming a new deployment is configured correctly, or auditing whether a public API allows credentialed calls.

Endpoint: https://cors-header-checker.underscoredone.com/check
Price: $0.01 / call
Settles via: cdp
Category: —
Last seen live: Tue, 08 Sep 2026 05:23:37 UTC
Last probed: Tue, 08 Sep 2026 05:23:37 UTC
First indexed: Tue, 08 Sep 2026 05:22:22 UTC
Sources: cdp-x402

Probe history

Last 1 probes, newest on the right. 100% answered with a payment challenge.

When	Result	Method	Status	Latency
Tue, 08 Sep 2026 05:23:37 UTC	challenge	http-402	402	598 ms

JSON: /api/v1/services/cors-header-checker.underscoredone.com. Own this service? Update the listing.