Search and reference HTTP status codes. Understand responses from web servers and APIs.
Request can continue, client should send body
Server switches protocols
Server is processing request (WebDAV)
Request succeeded, response body contains result
Resource created successfully, Location header provided
Request accepted but not completed
Request succeeded, no content to return
Partial content returned (range request)
Multiple representations of resource available
Resource moved to new URL (update bookmarks)
Type a code, name, or keyword to search through all status codes
404 Not Found means the server cannot find the requested resource. The URL doesn't exist, the page was moved without a redirect, or the resource was deleted. It's a client error indicating the request was valid but the resource doesn't exist at that location.
200 OK indicates a successful request for any general operation. 201 Created specifically indicates a POST or PUT request successfully created a new resource. Use 201 when a new resource is created, 200 for updates or successful GET requests.
Use 403 Forbidden when the resource exists but the user lacks permission to access it. Use 404 Not Found when the resource doesn't exist or you don't want to reveal its existence to unauthorized users. 403 says 'I know it's there but you can't have it', 404 says 'nothing here'.
500 Internal Server Error is a generic server-side error when something unexpected happens. Common causes include: unhandled exceptions in code, database connection failures, misconfigured servers, insufficient permissions, or resource exhaustion. Check server logs for specific details.
3xx codes indicate redirection. 301 is permanent redirect (moved forever), 302 is temporary redirect (moved temporarily), 304 is not modified (use cached version), and 307/308 are temporary/permanent redirects that preserve the HTTP method. Browsers automatically follow redirects.
Use 2xx for success (200 for GET/UPDATE, 201 for CREATE, 204 for DELETE with no content), 4xx for client errors (400 bad request, 401 unauthorized, 404 not found, 422 validation failed), and 5xx only for genuine server errors. Be specific - proper status codes improve API clarity.
HTTP status codes are three-digit numbers that communicate the result of HTTP requests. Understanding them is essential for developers working with APIs, web services, and web applications.