HTTP 304 Not Modified indicates the resource has not changed since the version identified by the conditional headers (If-Modified-Since or If-None-Match). The server returns no body, telling the client to use its cached copy. This is the foundation of HTTP caching validation — it lets the server confirm the client's cache is still fresh without retransmitting the resource, saving bandwidth and improving load times.
Response includes the status code, standard headers (including Content-Type), and a small diagnostic JSON body describing the request and returned status.
Simulator URL (copy in the app after load — not a normal link):
https://httpstatus.com/api/status/304
Example request:
curl -i "https://httpstatus.com/api/status/304"