HEAD request method

The HEAD HTTP method requests the metadata of a resource in the form of headers that the server would have sent if the {{HTTPMethod("GET")}} method was used instead. This method can be used in cases where a URL might produce a large download, for example, a HEAD request can read the {{HTTPHeader("Content-Length")}} header to check the file size before downloading the file with a GET.

If the response to a HEAD request shows that a cached URL response is now outdated, the cached copy is invalidated even if no GET request was made.

[!WARNING] If a response to a HEAD request has a body, the response body must be ignored. Any {{glossary("Representation header", "representation headers")}} that describe the erroneous body are assumed to describe the response body that a GET request would have received.

Syntax

HEAD <request-target>["?"<query>] HTTP/1.1

• <request-target>
  • : Identifies the target resource of the request when combined with the information provided in the {{HTTPHeader("Host")}} header. This is an absolute path (e.g., /path/to/file.html) in requests to an origin server, and an absolute URL in requests to proxies (e.g., http://www.example.com/path/to/file.html).
• <query> {{optional_inline}}
  • : An optional query component preceded by a question-mark ?. Often used to carry identifying information in the form of key=value pairs.

Examples

Successfully retrieving resource metadata

The following curl command creates a HEAD request for example.com:

curl --head example.com

This is the equivalent to a GET request, except the server shouldn't include a message body in the response. It creates an HTTP request that looks like this:

HEAD / HTTP/1.1
Host: example.com
User-Agent: curl/8.6.0
Accept: */*

The server sends back a {{HTTPStatus("200", "200 OK")}} response comprised only of headers. The response is effectively metadata that describes the resource instead of the resource itself (some caching headers are omitted in this example for brevity):

HTTP/1.1 200 OK
Content-Type: text/html; charset=UTF-8
Date: Wed, 04 Sep 2024 10:33:11 GMT
Content-Length: 1234567

Specifications

{{Specifications}}

Browser compatibility

{{Compat}}

See also

• HTTP request methods
• HTTP response status codes
• HTTP headers
• {{HTTPMethod("GET")}} method