204 No Content
204 No Content should be returned by a server when a request was
successful, but there was no response body.
For most APIs, the following two responses are the same:
HTTP/1.1 200 OK
Content-Length: 0
HTTP/1.1 204 No Content
The second format has a slight preference by most API designers. The reason
there is a separate status-code, is because the 204 No Content response can
signal a hypermedia client to not change the document and just stay on the
current ‘view’. For example, a client might ‘save’ a document temporarily and
not refresh to a new page.
Personally I have not really seen this behavior, but I can absolutely see this as a real possibility for a true HATEOAS client.
However, most of the time, 204 is simply used as a stand-in for 200 without
a response body.
204 No content is sometimes misunderstood by implementors of HTTP APIs to
indicate that the target resource ‘no longer has any contents’ after a
DELETE request. However, other successful requests that don’t have a
response body should also have the 204 No Content status, including PUT
and POST.
References
- RFC7231 -
204status code.