Free HTTP headers checker. Inspect every response header from any URL, with per-phase timing (DNS, connect, TLS, time-to-first-byte, total) measured from our London probe, the full redirect chain, status code, and Server signature. Choose the method, follow redirects, and send a custom User-Agent or request headers. Use it to debug deployments, audit security headers (CSP, HSTS, X-Frame-Options), and verify CDN configuration.
