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  4. Request methods
  5. OPTIONS

OPTIONS request method

Baseline
Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.

The OPTIONS HTTP method requests permitted communication options for a given URL or server. This can be used to test the allowed HTTP methods for a request, or to determine whether a request would succeed when making a CORS preflighted request. A client can specify a URL with this method, or an asterisk (*) to refer to the entire server.

Request has body May*
Successful response has body May
Safe Yes
Idempotent Yes
Cacheable No
Allowed in HTML forms No

* Although an OPTIONS message with a request body is technically allowed, it has no defined semantics. You may include a body in an OPTIONS message as long as you provide a valid Content-Type header, and when you know the server expects it, as behavior is implementation-specific.

Syntax

http
OPTIONS *|<request-target>["?"<query>] HTTP/1.1

The request target may be either in 'asterisk form' * indicating the whole server, or a request target as is common with other methods:

*

Indicates that the client wishes to request OPTIONS for the server as a whole, as opposed to a specific named resource of that server.

<request-target>

Identifies the target resource of the request when combined with the information provided in the 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

An optional query component preceded by a question-mark ?. Often used to carry identifying information in the form of key=value pairs.

Examples

Identifying allowed request methods

To find out which request methods a server supports, one can use the curl command-line program to issue an OPTIONS request:

bash
curl -X OPTIONS https://example.org -i

This creates the following HTTP request:

http
OPTIONS / HTTP/2
Host: example.org
User-Agent: curl/8.7.1
Accept: */*