OPTIONS

The HTTP OPTIONS method requests permitted communication options for a given URL or server. A client can specify a URL with this method, or an asterisk (*) to refer to the entire server.

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

Syntax

OPTIONS /index.html HTTP/1.1
OPTIONS * HTTP/1.1

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:

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

The response then contains an Allow header that holds the allowed methods:

HTTP/1.1 204 No Content
Allow: OPTIONS, GET, HEAD, POST
Cache-Control: max-age=604800
Date: Thu, 13 Oct 2016 11:45:00 GMT
Server: EOS (lax004/2813)

Preflighted requests in CORS

In CORS, a preflight request is sent with the OPTIONS method so that the server can respond if it is acceptable to send the request. In this example, we will request permission for these parameters:

  • The Access-Control-Request-Method header sent in the preflight request tells the server that when the actual request is sent, it will have a POST request method.
  • The Access-Control-Request-Headers header tells the server that when the actual request is sent, it will have the X-PINGOTHER and Content-Type headers.
OPTIONS /resources/post-here/ HTTP/1.1
Host: bar.example
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-us,en;q=0.5
Accept-Encoding: gzip,deflate
Connection: keep-alive
Origin: https://foo.example
Access-Control-Request-Method: POST
Access-Control-Request-Headers: X-PINGOTHER, Content-Type

The server now can respond if it will accept a request under these circumstances. In this example, the server response says that:

Access-Control-Allow-Origin
The https://foo.example origin is permitted to request the bar.example/resources/post-here/ URL via the following:
Access-Control-Allow-Methods
POST, GET, and OPTIONS are permitted methods for the URL. (This header is similar to the Allow response header, but used only for CORS.)
Access-Control-Allow-Headers
Any script inspecting the response is permitted to read the values of the X-PINGOTHER and Content-Type headers.
Access-Control-Max-Age
The above permissions may be cached for 86,400 seconds (1 day).
HTTP/1.1 204 No Content
Date: Mon, 01 Dec 2008 01:15:39 GMT
Server: Apache/2.0.61 (Unix)
Access-Control-Allow-Origin: https://foo.example
Access-Control-Allow-Methods: POST, GET, OPTIONS
Access-Control-Allow-Headers: X-PINGOTHER, Content-Type
Access-Control-Max-Age: 86400
Vary: Accept-Encoding, Origin
Keep-Alive: timeout=2, max=100
Connection: Keep-Alive

Specifications

Specification Title
RFC 7231, section 4.3.7: OPTIONS Hypertext Transfer Protocol (HTTP/1.1): Semantics and Content

Browser compatibility

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
OPTIONSChrome Full support YesEdge Full support 12Firefox Full support YesIE Full support YesOpera Full support YesSafari Full support YesWebView Android Full support YesChrome Android Full support YesFirefox Android Full support YesOpera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support Yes

Legend

Full support  
Full support

See also