HTTP Headers fetches a URL and displays the complete set of request and response headers, so you can inspect caching directives, content types, server signatures and custom headers the browser exchanges with the origin.
Enter a full URL (https://example.org) and run the tool. The probe performs an HTTP request and dumps every header sent and received.
Input: URL — e.g. https://example.org.
The output is split into request headers (what the probe sent) and response headers (what the server returned), followed by the final status code. Look for caching headers to tune CDN behaviour, the Server header to identify the software, and Set-Cookie / Content-Security-Policy headers to audit behaviour.
→ Inspect caching headers to tune CDN or browser cache behaviour.
→ Identify the server software and version behind a site.
→ Audit Set-Cookie and security headers on a response.
→ Debug why a cached resource is not updating.
Cache-Control tells caches (browsers, CDNs) how and for how long to store the response. max-age sets the freshness lifetime in seconds; no-cache forces revalidation; public/private controls whether shared caches may store it. Tune it to balance performance with freshness.
Obscuring the Server header removes a small information leak about your stack, but it is not a meaningful security control on its own. It is fine to suppress it, but prioritise keeping the software patched over hiding its version.
This probe sends a generic user agent and no cookies, so servers may respond differently than to a real browser (different Vary, cookies, or content). For an exact match, replicate the browser’s request headers.