HTTP Status Codes
Complete reference of HTTP status codes with descriptions.
Type a status code number or keyword to filter. Try "404", "redirect", or "timeout".
What Are HTTP Status Codes?
HTTP status codes are three-digit numbers returned by a web server in response to a client's request. They indicate whether a request was successful, redirected, resulted in an error, or requires further action. Every time your browser loads a page, fetches an image, or calls an API, the server responds with one of these codes along with the requested content or an error message.
Status Code Categories
The codes are grouped into five categories. 1xx (Informational) codes signal that the server received the request and is continuing to process it. 2xx (Success) codes confirm that the request was received, understood, and accepted — 200 OK being the most common. 3xx (Redirection) codes tell the client to look elsewhere, such as 301 Moved Permanently for SEO-safe URL changes. 4xx (Client Error) codes indicate a problem with the request itself — 404 Not Found means the resource does not exist, while 403 Forbidden means access is denied. 5xx (Server Error) codes point to a problem on the server side, like 500 Internal Server Error or 503 Service Unavailable during maintenance.
Common Codes Every Developer Should Know
The most frequently encountered codes are 200 (OK), 301 (Moved Permanently), 302 (Found/Temporary Redirect), 400 (Bad Request), 401 (Unauthorized), 403 (Forbidden), 404 (Not Found), 429 (Too Many Requests), 500 (Internal Server Error), and 503 (Service Unavailable). Understanding these helps you debug API integrations, fix broken links, configure proper redirects, and diagnose server issues quickly.
Using This Reference
Search by code number or keyword to find any status code instantly. Use the category pills to browse by group. Each entry includes the official name and a plain-English explanation of what the code means and when it typically occurs.