Searchable reference for common HTTP status codes, meanings, and response categories.
Loading tool
About HTTP Status Code Cheat Sheet
Searchable reference of HTTP status codes from 1xx to 5xx with a short description and the defining spec for each. Search by number, a class like 5xx, a name such as 'Not Found', or a keyword like 'redirect' or 'rate limit'. Vendor-specific codes from nginx, Cloudflare, IIS and others are included and can be hidden.
Common uses
- Choose the right status code for an API response
- Look up an unfamiliar code from a log, such as 499 or 522
- Explain the difference between similar redirects or client errors
- Copy a code and its reason phrase into documentation
FAQ
- What is the difference between 401 and 403?
- 401 Unauthorized means the request lacks valid authentication credentials. 403 Forbidden means the server understood who you are (or does not care) and refuses access anyway.
- What is the difference between 301, 302, 307 and 308?
- 301 and 308 are permanent redirects; 302 and 307 are temporary. 307 and 308 require the client to repeat the same method and body, while 301 and 302 allow clients to change POST to GET.
- What is the difference between 502 and 504?
- Both come from a gateway or proxy. 502 Bad Gateway means the upstream server returned an invalid response; 504 Gateway Timeout means it did not respond in time.
- What does 499 mean?
- 499 Client Closed Request is a non-standard nginx code logged when the client closes the connection before the server sends a response.