HTTP Status Codes
HTTP 203 Non-Authoritative Information
Non-Authoritative Information — response was modified by an intermediary proxy
Status 203 indicates that the request was processed successfully by the origin server, but an intermediate proxy or gateway transformed the response metadata or content before reaching the client.
Visual summary
A quick reference view of how HTTP 203 works: A payload passing through an intermediary node and receiving a modification tag.
What 203 Means
The shortest useful reading of this status code.
Non-Authoritative Information means response was modified by an intermediary proxy.
This status falls into the 2xx class, indicating a successful outcome for the request.
Quick read
Non-Authoritative Information
response was modified by an intermediary proxy
Technical Context
How this status behaves without turning the page into a repair guide.
Standard usage
The 203 Non-Authoritative Information code signals that while the operation was successful (equivalent to 200 OK at the origin), the payload has undergone transformation by an intermediate system.
Technical nuance
In modern network architectures, status 203 is an integrity signal. It allows clients requiring byte-exact validation to detect when intermediate systems have altered payload attributes.
Related HTTP Codes
Nearby HTTP status codes help clarify how 203 differs inside the same response family.
203
Non-Authoritative Information
response was modified by an intermediary proxy
200
OK
the request succeeded and the server returned the expected response
204
No Content
the request was successful but there is no content to return
206
HTTP 206 Partial Content
the server is sending a requested range
Common Causes
Transforming proxy modified headers or payload data before forwarding to client
A common condition that triggers a 203 response when the web server evaluates the transaction.
Corporate security gateway injected metadata into the response stream
A common condition that triggers a 203 response when the web server evaluates the transaction.
Edge caching layer altered asset packaging or compression format
A common condition that triggers a 203 response when the web server evaluates the transaction.
Typical Scenarios
An enterprise gateway appends compliance metadata to outbound API responses
A web accelerator compresses and reformats response assets on behalf of mobile clients
A proxy cache serves modified headers indicating alternative source routing
What To Know
A 203 response indicates operational success with payload modification. Applications requiring raw origin authenticity should evaluate intermediate proxy configurations.
Frequently Asked Questions
Common interpretation questions about HTTP 203.
The content is generally usable, but it may not be identical to what the origin server originally sent. Applications that need byte-exact fidelity should verify against the origin directly.