The HTTP203 Non-Authoritative Informationsuccessful response status code indicates that the request was successful, but atransformingproxy has modified the headers or enclosed content from the origin server's200 (OK) response.

The purpose of this status code is to allow transforming proxies to notify clients when changes have been applied to successful responses, since this may impact decisions regarding the content later.Transformations to messages can mean modifications of headers to indicate that a resource is from a mirror or a backup, but may also mean modifying content in a way that are presumed to be desirable to the client.These modifications might include malware filtering, format transcoding, privacy filtering, or other hints to the client about future requests.

The203 response is similar to the214Transformation Applied value of the deprecatedWarning header, which may be applicable to responses with any status code.

Status

203 Non-Authoritative Information

Examples

Receiving a filtered message response

In this example, a user sends aGET request for content with ID123 toexample.com.

GET /comments/123 HTTP/1.1Host: example.com

A proxy has altered the message based on malware filtering rules for known unsafe attachments.The response content has been modified, replacing theattachment_url value to a link with information about the filtering in place:

HTTP/1.1 203 Non-Authoritative InformationDate: Wed, 26 Jun 2024 12:00:00 GMTServer: Apache/2.4.1 (Unix)Content-Type: application/jsonContent-Length: 123{  "comment": "Check out my bio!",  "attachment_url": "https://example.com/attachment-unavailable-faq"}

Specifications

See also

• 200
• Proxy server
• Warning
• HTTP request methods
• HTTP response status codes