HTTP Status Code Reference

Understanding HTTP Status Codes

Every time you visit a webpage, your browser communicates with a web server using HTTP. When the server responds, it attaches a three-digit status code. While you usually only see them when something goes wrong (like a 404 page), they are happening behind every single request.

The 5 Categories of HTTP Codes

Status codes are divided into five classes based on their first digit, making it easy to instantly know the category of the response:

• 1xx (Informational): The request was received and processing continues.
• 2xx (Success): The request was successfully received, understood, and accepted.
• 3xx (Redirection): Further action needs to be taken by the client to complete the request.
• 4xx (Client Error): The request contains bad syntax or cannot be fulfilled. It's the client's fault.
• 5xx (Server Error): The server failed to fulfill an apparently valid request. It's the server's fault.

Common Questions

Why am I getting a 500 Internal Server Error?

This is a catch-all error indicating something went wrong on the server's backend. It could be a database connection failure, a syntax error in the server script, or a missing file requirement. As an end-user, there is nothing you can do but wait for the site owner to fix it.

Should I use 401 or 403 for unauthorized access?

Strictly speaking, 401 Unauthorized actually means unauthenticated (the client must log in). 403 Forbidden means unauthorized (the client is logged in, but lacks permissions to access the resource).