HTTP Response Code Checker
Look up any HTTP response code and understand its meaning for web development.
Quick Reference
Understanding HTTP Response Codes
HTTP response codes (also called status codes) are standardized codes returned by web servers to indicate the result of a client's request. These three-digit numbers communicate whether a request succeeded, failed, or requires additional action.
Web developers and system administrators rely on response codes for debugging, monitoring, and optimizing web applications. Understanding these codes helps diagnose issues quickly and implement proper error handling.
Response Code Categories
Codes are organized into five categories: 1xx (Informational), 2xx (Success), 3xx (Redirection), 4xx (Client Error), and 5xx (Server Error). The first digit indicates the category, while the remaining digits provide specifics.
Most Common Response Codes
200 OK is the standard success response. 404 Not Found indicates missing resources. 500 Internal Server Error signals server-side problems. 301 and 302 handle permanent and temporary redirects respectively.
Response Codes in APIs
RESTful APIs rely heavily on HTTP status codes for communication. 201 indicates successful creation, 400 signals bad request parameters, 401/403 handle authentication and authorization failures.
Monitoring Response Codes
Set up monitoring to track unusual response code patterns. Spikes in 5xx errors indicate server issues. Increasing 404 errors may signal broken links or deleted content that needs redirects.