2xx Series: Status codes indicating the request was successfully processed.
Code
Meaning
200
The server successfully processed the request and returned the requested webpage.
204
The server successfully processed the request, but is not returning any content.
3xx Series: Redirection. Do not use more than 5 redirects in a single request.
Code
Meaning
301
The requested webpage has been permanently moved to a new location. Use the 301 code when URLs change. Search engine indexes save the new URL.
302
The requested webpage has been temporarily moved to a new location. Search engine indexes save the original URL.
304
If a webpage has not been updated since the requester last requested it, use the 304 code to tell search engine bots, saving bandwidth and overhead.
4xx Series: Client errors, indicating the request may be erroneous and preventing the server from processing it.
Code
Meaning
400
The server does not understand the syntax of the request.
403
The server refused the request.
404
The server cannot find the requested webpage. Nonexistent pages on the server often return this code.
5xx Series: Server errors, indicating the server encountered an internal error while processing the request. These errors are usually issues with the server itself, not with the request.
Code
Meaning
500
The server encountered an error and could not complete the request.
503
The server is currently unavailable (due to overload or maintenance). Typically, this is just a temporary state.
