HTTP Status Code Lookup

Every HTTP response includes a status code that tells the client how the request was handled. The first digit sets the class — for example, anything in the 4xx range means the client's request had a problem, while 5xx means the server failed. Knowing the category alone often points you to the cause.

Status codes are grouped by their first digit: 1xx informational, 2xx success, 3xx redirection, 4xx client error and 5xx server error.

404 is "Not Found", a client error meaning the server cannot find the requested resource.

1. Enter a status code such as 404.
2. Read its name, category and meaning.

• Confusing 401 (not authenticated) with 403 (authenticated but forbidden).
• Returning 200 for an error instead of an appropriate 4xx or 5xx.
• Treating a 3xx redirect as an error.

The HTTP Status Code Lookup explains what any standard HTTP response code means — its name, category and a plain-English description — from informational 1xx codes to server-error 5xx codes.

Web developers, API users, QA engineers and anyone debugging a request.

• Name, category and meaning for each code.
• Covers common and less common standard codes.
• Grouped by class so you understand the pattern.
• Private — looked up entirely in your browser.

• Decoding an unexpected response while debugging.
• Checking the right code to return from an API.
• Learning what each status class means.