404Not Found
404 Not Found means the server did not find a current representation for the target resource, or is not willing to disclose that one exists. The URL is valid enough to route; the resource behind it is missing.
What does it mean?
A 404 does not say whether the absence is temporary or permanent. If the server knows the resource is permanently gone, 410 Gone is more precise.
A 404 response is heuristically cacheable. That is useful for missing assets, but it also means a temporary mistake can stick in caches if you are not careful.
When does it happen?
- A URL was renamed or deleted without a redirect.
- A path has a typo or the wrong API version.
- A record was deleted and the detail page still links to it.
- A route exists but the requested file or slug does not.
How do you fix it?
If you run the server
- Add 301 or 308 redirects for renamed URLs that should keep working.
- Return 410 Gone for resources you know are permanently removed.
- Check for soft 404s: a page that returns 200 while telling the visitor “not found”.
- Make the 404 page useful: link back to the index, search, or the nearest relevant page.
If you are just visiting
- Check the URL for typos.
- Go back to the index and search for the page.
- If you followed a link from this site, the link is the bug; tell us.
