4xx Client Errors
HTTP 404 Not Found
The server cannot find the requested resource. The most common error on the web.
When is 404 used?
- Broken links
- Non-existent API endpoints
- Deleted resources
How to handle a 404 response
Inspect the request — URL, method, headers, credentials, and body. Retrying the same request unchanged will usually fail again; 429 is the exception, where you should wait for the Retry-After period.
Check the status code a URL returns from the command line:
curl -s -o /dev/null -w "%{http_code}\n" https://example.comHow to return 404 from your server
Node.js (Express)
res.status(404).json({ message: 'Not Found' });Python (Flask)
return {"message": "Not Found"}, 404Go (net/http)
w.WriteHeader(404)Frequently Asked Questions
What does HTTP 404 mean?
404 Not Found: The server cannot find the requested resource. The most common error on the web.
Is 404 an error?
Yes. 404 is in the 4xx Client Errors class. Client errors: the request is malformed, unauthorized, or targets something that does not exist.