HTTP Header Checker — Inspect Server Response Headers
Inspect raw HTTP response headers for any URL. Check caching headers, content-type, CORS, and security headers. Free HTTP header analyzer for SEO.
What is a HTTP Header Checker?
The HTTP Header Checker fetches the raw response headers for any URL and displays them in a structured, readable format. Every header returned by the server is shown — status line, content-type, cache-control, content-encoding, server, set-cookie, strict-transport-security, x-powered-by, x-robots-tag, and any custom headers — giving you a complete view of exactly what the server is communicating to browsers and crawlers on each request.
When Should You Use HTTP Header Checker?
Use this when debugging caching behaviour, verifying HTTPS redirects and HSTS configuration, checking whether compression is active, confirming CDN headers are injecting correctly, or investigating why a page behaves differently in different environments. For technical SEO, the most important headers to check are x-robots-tag (which can block indexing at the server level, overriding the meta robots tag in the HTML), the location header on redirect responses, and cache-control directives that may cause stale content to be served to Googlebot.
How to Read HTTP Header Checker Results
The status line at the top confirms the HTTP response code for the URL as fetched. Check cache-control and expires for caching behaviour — pages with no cache directives are re-fetched on every request, increasing server load and slowing response times. Content-encoding: gzip or br confirms compression is active, which directly affects page load speed. Strict-transport-security confirms HTTPS enforcement is configured at the header level rather than relying solely on server-side redirects.
What Should You Know Before Using HTTP Header Checker?
If a page is being blocked from indexing and the meta robots tag looks correct, check for an x-robots-tag header — this is a common source of unexpected noindex signals on pages served through certain CDNs or middleware layers. Compare headers between production and staging environments when a page behaves differently across environments — discrepancies in cache-control, x-robots-tag, or content-type headers explain most environment-specific SEO bugs that are invisible in the HTML source.
Frequently Asked Questions
What are HTTP response headers?
HTTP response headers are key-value pairs sent by a web server alongside the page content in response to a browser or crawler request. They control caching behaviour, content type, compression, security policies, redirect targets, and indexing directives. They are invisible in the browser but can be inspected with the HTTP Header Checker or browser DevTools.
How do I check HTTP headers for any URL?
Enter any URL into the HTTP Header Checker and the tool fetches the raw response headers, displaying them in a structured, readable format. All headers returned by the server are shown — including status code, content-type, cache-control, content-encoding, strict-transport-security, and any custom or x-robots-tag headers set by the server or CDN.
What is the X-Robots-Tag header?
X-Robots-Tag is an HTTP response header that provides indexing directives (noindex, nofollow, noarchive) at the server level rather than via an HTML meta tag. It works for any file type, including PDFs and images. If a page appears to be indexed despite having a noindex meta tag, check for a conflicting X-Robots-Tag header that overrides the HTML directive.
How do I check if HTTPS is correctly configured?
Use the HTTP Header Checker to inspect the Strict-Transport-Security header (HSTS) — its presence confirms HTTPS enforcement at the header level. Also check that requesting http:// returns a 301 redirect to https://, visible in the status code and Location header. If the server returns 200 on HTTP without redirecting, HTTPS is not being enforced.
What cache-control headers mean for SEO?
Cache-Control headers tell browsers and CDNs how long to cache a response. For Googlebot, they influence how frequently a page is recrawled — a very long max-age may cause Googlebot to serve stale content to searchers rather than recrawling the latest version. For most content pages, a max-age of 1–7 days is appropriate. Static assets like images can have much longer cache times.
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