HTTP Status Codes
Complete list of 62 HTTP status codes with clear explanations, causes and fixes. Search by code or name.
Or browse all codes by class ↓
Most searched
All codes by class
Informational (1xx) (4)
Provisional responses that tell the client the request was received and processing continues.
Success (2xx) (10)
The request was successfully received, understood and accepted.
Redirection (3xx) (8)
Further action (usually a redirect) is needed to complete the request.
Client errors (4xx) (29)
The request contains an error from the client — bad syntax, missing auth or a wrong URL.
Server errors (5xx) (11)
The server failed to fulfil an apparently valid request.
Frequently asked questions
What is an HTTP status code?
An HTTP status code is a three-digit number the server returns with every response to describe the outcome of a request. The first digit sets the class: 1xx informational, 2xx success, 3xx redirection, 4xx client error, 5xx server error.
What is the difference between 4xx and 5xx?
4xx codes mean the problem is on the client side (wrong URL, missing auth, invalid data), while 5xx codes mean the server failed to handle an otherwise valid request. In short: 4xx "you erred", 5xx "the server erred".
Which status codes are the most common?
200 OK (success), 301/302 (redirects), 304 (cached), 400 (bad request), 401/403 (authorization), 404 (not found), 429 (too many requests), 500 (internal error), 502/503/504 (gateway/availability problems).
Do status codes affect SEO?
Yes. 200 is ideal; 301 transfers ranking on a permanent move; 404 and 410 tell search engines a page is gone (410 more definitively); repeated 5xx errors can hurt indexing.
Where does the data come from?
Codes follow the IANA HTTP Status Code Registry and the relevant RFC specifications (RFC 9110 and others). Everything runs in your browser — no external requests, no tracking.