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HTTP Header Checker – View a URL's Response Headers

See every response header a URL sends, with the common ones explained in plain words.

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About HTTP Header Checker

An HTTP header checker answers questions a browser hides: is the page coming from the CDN's cache, how long may browsers keep it, which server software answers, does an X-Robots-Tag say noindex, or why does a file download instead of opening. Enter a URL and you get the status line, the HTTP version, the response time, any redirect hops and every header exactly as the server sent it.

About 50 common headers, from Cache-Control and Content-Type to Strict-Transport-Security and X-Robots-Tag, get a short explanation beside them. Choose GET or HEAD, pick a user agent such as Googlebot or Baiduspider under Visit as, and untick Follow redirects to see a redirect response itself. The request headers we sent are listed too, and Copy puts all the response headers on your clipboard. For a graded view of the security headers, use the Security Headers Checker.

How to use HTTP Header Checker

  1. 1
    Enter the URL

    Paste the address of a page, an image or any file you want to inspect.

  2. 2
    Set the request

    Choose GET or HEAD, pick who visits, and decide whether to follow redirects.

  3. 3
    Click Check

    The request goes out from our server and the answer comes back with every header.

  4. 4
    Read or copy

    Known headers show their meaning under the name, and Copy takes them all.

Why use Cubfile for this

  • Every header, as sent

    Names and values exactly as the server returned them, in their original order.

  • Plain explanations

    About 50 common headers are explained in a line each.

  • GET or HEAD

    Send HEAD when you only need headers, or GET to see what a normal visit returns.

  • Redirects your way

    Follow them to the final page, or stop at the first answer to inspect the 301 itself.

FAQ

HTTP Header Checker: questions and answers

What's the difference between GET and HEAD?
GET asks for the page the way a browser does. HEAD asks for the headers only, and some servers answer it differently or not at all, so compare both if a result looks odd.
Why don't I see Content-Encoding: br?
This check asks for gzip and deflate only, so a server that supports Brotli will usually answer with gzip here. To see every compression a page supports, use the GZIP and Brotli Checker.
Can I see the headers of a redirect instead of the final page?
Yes. Untick Follow redirects and you get the 301 or 302 response itself, including its Location header. To follow the whole chain hop by hop, use the Redirect Checker.
Which headers does the HTTP header checker explain?
About 50 common ones, including Cache-Control, Content-Type, Set-Cookie, Strict-Transport-Security, Content-Security-Policy, Vary, X-Robots-Tag and CDN headers such as CF-Cache-Status. Rare or custom headers are shown without a note.
Is it free, and are my lookups stored?
It's free with no sign-up and doesn't use daily tasks. The check runs when you click, the result isn't stored, and only public internet addresses can be fetched.
Share HTTP Header Checker with a friendIt runs in any browser, and they can try it without signing up.

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