list_alt HTTP Header Viewer
Fetch any URL and inspect its full response headers - security, caching, CORS and more.
Enter a URL above and click Inspect to view its response headers.
This tool fetches a URL and displays exactly what HTTP response headers it returns - useful for debugging caching behavior, checking security headers, verifying redirects, or understanding how a server is configured to respond, without needing browser developer tools open.
Frequently asked questions
Common ones include Content-Type, Cache-Control, Set-Cookie, security headers like Content-Security-Policy, and server information - exactly what the target server chooses to send back.
Publicly accessible URLs generally work; some servers may block requests that don't look like they're coming from a real browser, which could affect what headers you see.
Common reasons: debugging why caching isn't working as expected, verifying security headers are configured correctly, or understanding a redirect chain when a URL doesn't go where you expect.