Explain CORS and test preflight. Check Access-Control-* headers. Fix CORS errors.
CORS Explainer and Tester: Explain CORS and test preflight. Check Access-Control-* headers. Fix CORS errors. Turns vague problems into specific findings by exposing what your systems actually sent and received. No server interaction after page load. Your data is never logged, stored, or transmitted. Open-access API Tools tool on HttpStatus.com.
It depends on what you're inspecting. Local data is analyzed in-browser; remote URLs require a request to fetch data.
No. All public tools work without an account. Accounts unlock saved history, workspaces, and team features.
Chrome, Firefox, Safari, and Edge — any modern browser. No plugins needed.