Complete list of HTTP response status codes with descriptions, use cases and examples. Search by code number or keyword to quickly find what you need for API development, debugging and server configuration.
Last updated: March 2026
Frequently Asked Questions
What are HTTP status codes and why are they important?
HTTP status codes are three-digit numbers returned by a web server in response to a client's request, standardized in RFC 7231 and related RFCs. They are grouped into five categories: 1xx (informational), 2xx (success), 3xx (redirection), 4xx (client error), and 5xx (server error). Understanding these codes is essential for API development, web server configuration, frontend error handling, SEO optimization, and debugging network issues.
What is the difference between 301 and 302 redirects?
A 301 Moved Permanently tells browsers and search engines the resource has permanently moved. Search engines transfer link equity (SEO ranking) to the new URL and update their index. A 302 Found indicates a temporary redirect — the original URL remains in search indexes. Using 301 when you mean 302 (or vice versa) can negatively impact your search rankings and user experience.
Which HTTP status codes should I use in my REST API?
Common REST API codes: 200 OK (successful GET/PUT), 201 Created (successful POST), 204 No Content (successful DELETE), 400 Bad Request (malformed input), 401 Unauthorized (missing authentication), 403 Forbidden (insufficient permissions), 404 Not Found, 409 Conflict (duplicate resource), 422 Unprocessable Entity (validation failure), and 500 Internal Server Error for unexpected failures.