The request is successful but the content of the original request has been modified by a transforming proxy.
What does HTTP 203 mean?
The 203 Non-Authoritative Information code is part of the 2XX class. This is a success code — the request was received, understood and processed successfully.
When is it used?
A server returns 203 Non-Authoritative Information in situations matching the definition above. You will encounter it inspecting network requests, reading logs, or testing an API. Whether it signals a problem depends on its class: 2xx and 3xx are normal, while 4xx and 5xx usually need attention on the client or server respectively.