HTTP Status Codes

403 Forbidden means the server understood your request but refuses to authorize it, so you simply lack permission for that resource. It is different from 401 Unauthorized, which really means unauthenticated: 401 says the server does not know who you are, while 403 says it knows and still says no. This searchable reference lists 403 alongside every other common code with a one-line meaning.

The first digit sorts every response into a class: 1xx is informational, 2xx is success, 3xx is a redirect, 4xx blames the request (a client error), and 5xx blames the server. Knowing just the class tells you which side to start debugging on before you even read the specific number. This tool groups its list under those five headings.

Type into the search box and the list filters live. You can search by the number (like 404), by the name (like "timeout" or "forbidden"), or by any word in the description, and matching rows are grouped by their class. Each row has a Copy button so you can grab the number in a click.

301 Moved Permanently says the resource has a new permanent URL and you should update your links, while 302 Found says it is only temporarily at a different URL. There are also 307 and 308, which behave like 302 and 301 respectively but guarantee the HTTP method will not change on the redirect. All four are in the 3xx section of this reference.

It is real in the sense that it is a registered code, but it started as an April Fools joke from 1998: a teapot politely refusing to brew coffee. You will not see it in normal APIs, though some servers use it playfully. It is included here in the 4xx list because people genuinely do look it up.