304 Not Modified — Causes & Fix
HTTP 304 (Not Modified) means the requested resource has not changed since the client last fetched it, so the server sends no body and the client uses its cached copy.
- Applies to
- Any website or web server (HTTP standard)
- Time to fix
- 5–30 minutes
What it means
Returned during caching (conditional requests using If-Modified-Since / ETag). It is normal and desirable, but stale-cache problems can cause outdated content. HTTP status 304 is defined in RFC 9110 (HTTP Semantics). This is a redirection (3xx) status — the client needs to take an additional step to complete the request.
Symptoms
- The resource loads from cache (fast, no body downloaded)
- Content may appear unchanged
How to fix it
- 1
Confirm caching is intended
1. 304 is normal — it saves bandwidth by serving cached content.
- 2
Force a refresh if content is stale
1. If you expect new content, hard-refresh or bump the asset version/ETag so the server sends a fresh copy.
Frequently asked questions
Is 304 an error?
No — it means "use your cached copy, nothing changed." It is a performance optimisation, not a failure.
Last updated July 20, 2026
Guidance only — always consult a qualified professional or the official service manual before carrying out repairs.