About HTTP status codes
This is a complete, searchable reference of HTTP status codes — the three-digit numbers a server returns to say how a request went. They are grouped into five classes: 1xx informational, 2xx success, 3xx redirection, 4xx client errors and 5xx server errors. Search by number or keyword to find what a code means.
How HTTP Status Codes works
How to use it
- Type a code (like 404) or a keyword (like redirect) in the search box.
- Filter by class with the 1xx–5xx tabs.
- Read the name and meaning of each code.
The five classes
1xx informational, 2xx success (e.g. 200 OK, 201 Created), 3xx redirection (301, 302, 304), 4xx client errors (400, 401, 403, 404, 429), and 5xx server errors (500, 502, 503).
Common uses
- Look up what a status code means
- Understand a 404 or 500 error
- Compare 301 and 302 redirects
- Debug an API response
- Learn HTTP status classes
- Find the right code to return
- Check rate-limit code 429
- Reference codes while coding
Frequently asked questions
What does 404 mean?
Not Found — the requested resource could not be located on the server.
What is the difference between 301 and 302?
301 is a permanent redirect; 302 is temporary.
What does 500 mean?
Internal Server Error — a generic server-side failure.
What is a 401 vs 403?
401 means authentication is required or failed; 403 means you are authenticated but not allowed.
What does 429 mean?
Too Many Requests — you have been rate limited.
Are these the official codes?
Yes — they are the standard IANA/RFC status codes.
What are 2xx codes?
Success responses such as 200 OK and 201 Created.
Is it free?
Yes — completely free with no sign-up.