HTTP Headers Checker

Enter a URL to see the response headers your server sends. Headers decide whether the page is compressed, how long browsers and CDNs may cache it and which security protections are enabled.

Free and without registration. The check is made from our server, so the timings include the network distance to it.

What this tool checks

All response headers of the final URL
Compression (gzip, Brotli, zstd) and protocol version (HTTP/2, HTTP/3 advertisement)
Caching headers: Cache-Control, Expires, ETag, Last-Modified
Security headers: HSTS, Content-Security-Policy, X-Content-Type-Options, X-Frame-Options, Referrer-Policy

Frequently asked questions

Why should responses be compressed?

Text resources like HTML, CSS and JavaScript shrink by 60-80% with gzip or Brotli, so pages download faster, especially on mobile networks. Compression is enabled on the web server (nginx, Apache) or the CDN.

Which security headers should every website have?

At least Strict-Transport-Security (forces HTTPS), X-Content-Type-Options: nosniff, a clickjacking protection (X-Frame-Options or the frame-ancestors directive of Content-Security-Policy) and a Referrer-Policy.

Why does the checker show headers of a different URL?

If the URL redirects, we follow the redirects and show the headers of the final page, because that is what visitors actually get. Use the redirect checker to see every step.

How does your website handle real traffic?

One request shows the best case. Run a free load test with up to 1,000 concurrent connections, compare the results after every change and get an email when your site goes down.

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