Non-Authoritative Information

2xx Success

ELI5

The request worked, but the response may have been adjusted by something in the middle, like a proxy, before it reached you.

Use 203 mainly from a transforming proxy when the origin's successful response was modified before delivery.

•Return 203 when an intermediary rewrites, adapts, or transforms the representation
•Use it to help clients understand that the payload is derived from a 200 response but not identical to it
•Transforming proxies that rewrite or optimize the origin response
•Intermediaries that adapt content and want to be explicit that the payload is not byte-for-byte authoritative
•Systems where the client should know a middle layer changed the original representation

•Preserve normal response metadata where possible and document proxy transformations clearly
•Use 200 instead when the origin server itself is intentionally returning that representation

•No status-specific header is required; preserve or document metadata affected by the intermediary transformation.

•Do not use 203 for ordinary application responses from the origin server
•Do not hide important data loss or semantic changes without making the transformation clear
•Origin servers returning their own authoritative representation
•Unmodified successful responses that should simply be 200 OK
•Application-level data shaping performed by the origin service itself

Request:GET https://api.example.test/news

Response:

203 Non-Authoritative Information

# Headers
Content-Type: text/html; charset=utf-8

# Body
<html><body>Transformed content</body></html>

A transforming intermediary changed the origin's response and signals that the payload is not exactly what the origin sent.

Everything worked perfectly! The server understood your request and sent back exactly what you asked for.

Success. The server did what you asked, but there’s nothing useful to send back in the body.

You already have the latest version! The thing you're asking for hasn't changed since you last got it.