AI engineering glossary · Web APIs HTTP
What is 304 Not Modified?
304 Not Modified: The status code returned when a client sent a conditional request and the cached copy is still current. The response has no body, saving bandwidth, and the client reuses what it stored.
304 Not Modified: an example
A client sends If-None-Match: "abc"; the server sees it matches and replies 304.
Related terms
More Web APIs HTTP terms
- 400 Bad Request
- 401 Unauthorized
- 403 Forbidden
- 404 Not Found
- 409 Conflict
- 422 Unprocessable Content
- 429 Too Many Requests
- 500 Internal Server Error
Where you learn it
304 Not Modified is part of the AI Engineering Program, which teaches it with notes, a hands-on lab and an exam. The first lesson is free.