| Status code | 304 |
|---|---|
| Status text | Not Modified |
| Category | 3xx Redirection |
| Response has body | No |
| Specification | RFC 9110 |
What does 304 Not Modified mean?
The cached copy the client already has is still valid, so no body is sent. It belongs to the 3xx Redirection class, which means further action is needed to complete the request, usually following a different URL.
When do APIs return 304?
You sent If-None-Match or If-Modified-Since and the resource has not changed.
How to fix a 304 Not Modified
Not an error — it is a bandwidth saving. If you want the full body while testing, remove the conditional request headers.
Reproduce a 304 response
The fastest way to understand a status code is to trigger one and read the full response. Open the
API tester and send a request to https://httpbin.org/status/304 — you will
see the 304 status along with every response header the server sent. Comparing those headers against
a working request is often what reveals the cause.
When you are debugging a real endpoint, check the response headers as carefully as the body, and confirm you are using the right HTTP method for the operation.
Related 3xx status codes
301 Moved Permanently
The resource has permanently moved to the URL in the Location header.
302 Found
The resource is temporarily at a different URL, but future requests should still use the original.
303 See Other
The response to the request can be found at another URL, and should be retrieved with GET.
307 Temporary Redirect
Like 302, but the HTTP method and body must be preserved when following the redirect.
308 Permanent Redirect
Like 301, but the method and body must be preserved.