Understanding HTTP Status Codes

Understanding HTTP Status Codes

HTTP status codes are three-digit numbers that a web server sends in response to a browser’s request. Understanding these codes helps you diagnose website issues and communicate effectively with your hosting provider.

Status Code Categories

Common Success Codes (2xx)

• 200 OK: The request was successful. This is the standard response for a successful page load.
• 201 Created: A new resource was successfully created (common in API responses).
• 204 No Content: The server processed the request but returned no content.

Common Redirection Codes (3xx)

• 301 Moved Permanently: The resource has permanently moved to a new URL. Search engines transfer link equity to the new URL.
• 302 Found (Temporary Redirect): The resource is temporarily at a different URL. Search engines keep indexing the original URL.
• 304 Not Modified: The resource hasn’t changed since the last request — the browser can use its cached version.
• 307 Temporary Redirect: Similar to 302 but preserves the HTTP method of the original request.
• 308 Permanent Redirect: Similar to 301 but preserves the HTTP method.

Common Client Error Codes (4xx)

• 400 Bad Request: The server can’t process the request due to malformed syntax.
• 401 Unauthorized: Authentication is required and has failed or not been provided.
• 403 Forbidden: The server understood the request but refuses to authorize it. Check file permissions.
• 404 Not Found: The requested resource doesn’t exist. Check URLs and set up a custom 404 page.
• 405 Method Not Allowed: The HTTP method used is not supported for the requested resource.
• 408 Request Timeout: The server timed out waiting for the request.
• 429 Too Many Requests: Rate limiting — too many requests in a given time period.

Common Server Error Codes (5xx)

• 500 Internal Server Error: A generic error indicating something went wrong on the server. Check error logs for details.
• 502 Bad Gateway: The server received an invalid response from an upstream server.
• 503 Service Unavailable: The server is temporarily unable to handle the request (maintenance or overload).
• 504 Gateway Timeout: The server didn’t receive a timely response from an upstream server.

How to Diagnose HTTP Errors

1. Check browser DevTools: Press F12 → Network tab to see status codes for every request.
2. Review server error logs: Access error_log via cPanel’s File Manager or FTP.
3. Test with cURL: Run curl -I https://yoursite.com to see response headers.
4. Use online tools: HTTPstatus.io or Redirect Checker can help trace redirect chains.

Fixing Common Issues