HTTP Status Codes Reference
Complete reference of HTTP response status codes with descriptions and common use cases.
Frequently Asked Questions
What are HTTP status codes?
HTTP status codes are 3-digit numbers returned by web servers to indicate the result of a client request. They are grouped into 5 classes: 1xx (informational), 2xx (success), 3xx (redirection), 4xx (client errors), and 5xx (server errors).
What is the difference between 401 and 403?
401 Unauthorized means the request lacks valid authentication credentials — logging in might fix it. 403 Forbidden means the server understood your identity but you do not have permission to access the resource — re-authenticating will not help.
What is the difference between 301 and 302?
301 is a permanent redirect — search engines transfer SEO value to the new URL. 302 is a temporary redirect — search engines keep the original URL indexed. Use 301 for permanent URL changes and 302 for temporary ones.