304
Not Modified
3xx Redirection
Class
RFC 9110 §15.4.5
Defined in
What does HTTP 304 mean?
The cached copy is still valid, so the server sends no body. Browsers send If-None-Match (with an ETag) or If-Modified-Since. If nothing changed, the server replies 304 and the browser reuses its cache — saving bandwidth and time.
3xx Redirection: The client must take another step — usually follow the URL in the Location header — to complete the request.
304 and SEO
Good for crawl efficiency: Googlebot supports conditional requests, and 304 responses save crawl budget on large sites.
Example response
HTTP/1.1 304 Not Modified
ETag: "33a64df5"
Cache-Control: max-age=600
Related status codes
- 200 OK — The request succeeded and the response body contains the requested resource.
- 412 Precondition Failed — A condition in the request headers (If-Match, If-Unmodified-Since) was not met.
Check which status code a URL returns with the HTTP header checker, or trace a redirect chain with the redirect checker.
All HTTP status codesSearch the full list of status codes from 100 to 599 with their meanings and SEO impact.
Open the full list Frequently asked questions
What does status code 304 mean?
304 Not Modified: The cached copy is still valid, so the server sends no body.
Does 304 affect SEO?
Good for crawl efficiency: Googlebot supports conditional requests, and 304 responses save crawl budget on large sites.