lightmy.dayINSTANT ANSWERS

Redirection

HTTP 304: Not Modified

HTTP 304 means the cached resource is still valid.

Meaning

The server is telling the client to reuse its cached copy.

Common causes

Conditional requests with If-None-Match or If-Modified-Since can return 304.

What to check

Check ETag, Last-Modified, Cache-Control, and stale cache behavior.

Example response

HTTP/1.1 304 Not Modified

References

Registry: IANA HTTP Status Code Registry
Spec: RFC 9110 §15.4.5
Guide: MDN 304 Not Modified

Related HTTP status codes

Nearby codes often answer the next debugging question.

200 OKHTTP 200 means the request succeeded.204 No ContentHTTP 204 means the request succeeded and there is no response body.300 Multiple ChoicesHTTP 300 means multiple response choices are available.