The HTTP 304
Not Modified
client redirection response code indicates that there is no need to retransmit the requested resources. It is an implicit redirection to a cached resource. This happens when the request method is {{glossary("safe")}}, like a {{HTTPMethod("GET")}} or a {{HTTPMethod("HEAD")}} request, or when the request is conditional and uses a {{HTTPHeader("If-None-Match")}} or a {{HTTPHeader("If-Modified-Since")}} header.
Many developer tools' network panels of browsers create extraneous requests leading to 304
responses, so that access to the local cache is visible to developers.
Status
304 Not Modified
Specifications
Specification | Title |
---|---|
{{RFC("7232", "304 Not Modified" , "4.1")}} | Hypertext Transfer Protocol (HTTP/1.1): Conditional Requests |
Browser compatibility
The compatibility table in this page is generated from structured data. If you’d like to contribute to the data, please check out https://github.com/mdn/browser-compat-data/README.md and send us a pull request.
{{Compat}}
See also
- {{HTTPHeader("If-Modified-Since")}}
- {{HTTPHeader("If-None-Match")}}