Appendix: OPTIONS object - Amazon Simple Storage Service
DescriptionRequestsResponsesExamplesRelated Resources

Appendix: OPTIONS object

Description

A browser can send this preflight request to Amazon S3 to determine if it can send an actual request with the specific origin, HTTP method, and headers.

Amazon S3 supports cross-origin resource sharing (CORS) by enabling you to add a cors subresource on a bucket. When a browser sends this preflight request, Amazon S3 responds by evaluating the rules that are defined in the cors configuration.

If cors is not enabled on the bucket, then Amazon S3 returns a 403 Forbidden response.

For more information about CORS, go to Enabling Cross-Origin Resource Sharing in the Amazon Simple Storage Service User Guide.

Requests

Syntax

OPTIONS /ObjectName HTTP/1.1
Host: BucketName.s3.amazonaws.com 
Origin: Origin
Access-Control-Request-Method: HTTPMethod
Access-Control-Request-Headers: RequestHeader

Request Parameters

This operation does not introduce any specific request parameters, but it may contain any request parameters that are required by the actual request.

Request Headers

Name Description Required
Origin

Identifies the origin of the cross-origin request to Amazon S3. For example, http://www.example.com.

Type: String

Default: None

 Yes
Access-Control-Request-Method

Identifies what HTTP method will be used in the actual request.

Type: String

Default: None

 Yes
Access-Control-Request-Headers

A comma-delimited list of HTTP headers that will be sent in the actual request.

For example, to put an object with server-side encryption, this preflight request will determine if it can include the x-amz-server-side-encryption header with the request.

Type: String

Default: None

 No

Request Elements

This implementation of the operation does not use request elements.

Responses

Response Headers

Header Description
Access-Control-Allow-Origin

The origin you sent in your request. If the origin in your request is not allowed, Amazon S3 will not include this header in the response.

Type: String
Access-Control-Max-Age

How long, in seconds, the results of the preflight request can be cached.

Type: String
Access-Control-Allow-Methods

The HTTP method that was sent in the original request. If the method in the request is not allowed, Amazon S3 will not include this header in the response.

Type: String
Access-Control-Allow-Headers

A comma-delimited list of HTTP headers that the browser can send in the actual request. If any of the requested headers is not allowed, Amazon S3 will not include that header in the response, nor will the response contain any of the headers with the Access-Control prefix.

Type: String
Access-Control-Expose-Headers

A comma-delimited list of HTTP headers. This header provides the JavaScript client with access to these headers in the response to the actual request.

Type: String

Response Elements

This implementation of the operation does not return response elements.

Examples

Example : Send a preflight OPTIONS request to a cors enabled bucket

A browser can send this preflight request to Amazon S3 to determine if it can send the actual PUT request from http://www.example.com origin to the Amazon S3 bucket named examplebucket.

Sample Request

OPTIONS /exampleobject HTTP/1.1
Host: examplebucket.s3.amazonaws.com 
Origin: http://www.example.com
Access-Control-Request-Method: PUT

Sample Response

HTTP/1.1 200 OK
x-amz-id-2: 6SvaESv3VULYPLik5LLl7lSPPtSnBvDdGmnklX1HfUl7uS2m1DF6td6KWKNjYMXZ
x-amz-request-id: BDC4B83DF5096BBE
Date: Wed, 21 Aug 2012 23:09:55 GMT
Etag: "1f1a1af1f1111111111111c11aed1da1"
Access-Control-Allow-Origin: http://www.example.com
Access-Control-Allow-Methods: PUT
Access-Control-Expose-Headers: x-amz-request-id
Content-Length: 0
Server: AmazonS3