HTTP Header Viewer: inspect any URL's response headers
Free in-browser HTTP header viewer. Get the status line, full response headers, final URL after redirects, and a security-header health check (HSTS, CSP, X-Frame-Options, Referrer-Policy). Cross-origin reads via corsproxy.io.
HTTP Header Viewer — frequently asked questions
Browsers block reading response headers from cross-origin requests unless the server allows it via CORS. A public CORS proxy (corsproxy.io) sits between us and the target so we can read every header.
The request originates from the corsproxy.io infrastructure with a normal browser user agent. Server logs will show the proxy's IP, not yours.
Servers and CDNs may strip headers for proxied requests, especially Set-Cookie. The proxy passes through what the target returned to it.