HTTP Status Codes
A complete reference for all HTTP status codes — search by number or name, filter by category, and learn what each code means.
Frequently Asked Questions
What are HTTP status codes?
HTTP status codes are three-digit numbers returned by a server in response to a client's request. They indicate whether the request was successful, redirected, resulted in a client error, or caused a server error. The first digit defines the category: 1xx informational, 2xx success, 3xx redirection, 4xx client error, 5xx server error.
How should I handle 4xx vs 5xx errors?
4xx errors indicate a problem with the request itself — wrong URL (404), missing authentication (401), invalid data (400). These are usually fixable by the client. 5xx errors indicate a server-side problem — the server crashed (500), is overloaded (503), or a gateway timed out (504). These require fixes on the server side and should be monitored and alerted on.
What is HTTP 418 "I'm a Teapot"?
HTTP 418 is an April Fools' joke from RFC 2324 (1998), the "Hyper Text Coffee Pot Control Protocol". Any attempt to brew coffee with a teapot should result in a 418 error. Despite being a joke, it is a real registered status code and is sometimes returned by servers as a way to reject unwanted requests.