Synonyms: HTTP response code
An HTTP status code is a three-digit number that a web server sends to a browser (or other client) in response to a request for a webpage or resource. These codes indicate the outcome of the request and help users, developers, and search engines understand whether a request was successful, encountered an error, or needs further action. Every time you visit a website, HTTP status codes are exchanged between your browser and the server to communicate what’s happening behind the scenes.
HTTP status codes are divided into five main categories:
- 1xx Informational: These codes indicate that the request is still being processed. Example: 100 Continue.
- 2xx Success: These mean the request was successfully received and processed. Example: 200 OK (the request was successful).
- 3xx Redirection: These codes mean further action is needed, usually involving redirection to another URL. Example: 301 Moved Permanently.
- 4xx Client Errors: These occur when the request has a problem from the client (user side). Example: 404 Not Found (the page doesn’t exist).
- 5xx Server Errors: These mean there’s an issue on the server side preventing the request from being completed. Example: 500 Internal Server Error.
Each of these codes provides important information for diagnosing and fixing issues with a website’s performance or functionality.