HTTP response codes

HTTP Response Codes come in ranges, the and most important digit in the range is the first (leftmost). The ranges can be read as follows:

• 1xx: Hold on
• 2xx: OK: Here you go
• 3xx: Go away
• 4xx: You messed up
• 5xx: I messed up

Code 1xx: Informational

1xx series messages just tell you the server is working on it - no status can be inferred from a message like this.

Code 2xx: Success

A code 200 is the ideal response; it means the request was successful.

Code 3xx: Redirection

These responses mean you are getting sent to another page, either temporarily or permanently.

Code 4xx: Client Error

The server is telling the client (the browser) it doesn’t know what is being asked for (eg: not found), or the request is unauthorized.

Code 500: Server Error

The server is telling the client it can’t respond, but it’s not the client’s fault.
These errors mean you need to check the logs. See 500 errors for more information.