HTTP Status Code Reference
Complete HTTP status code reference with interactive lookup. Find meanings for 2xx, 3xx, 4xx, 5xx status codes. Learn causes, solutions, and best practices for 400 Bad Request, 401 Unauthorized, 403 Forbidden, 404 Not Found, 500 Server Error, 503 Service Unavailable. Developer cheat sheet for debugging HTTP interactions.
Interactive HTTP status code lookup for developers
Find explanations for any HTTP status code instantly. Search by code number, status name, or description. View categorized responses: 200-299 Success (GET, POST, DELETE success codes), 300-399 Redirection (301 Moved Permanently, 304 Not Modified), 400-499 Client Errors (401 Unauthorized, 403 Forbidden, 404 Not Found, 429 Too Many Requests), 500-599 Server Errors (500 Internal Server Error, 502 Bad Gateway, 503 Service Unavailable). Includes causes, solutions, and recovery steps.
Common HTTP status codes and debugging strategies
401 Unauthorized - authentication failed or missing. Refresh tokens, check auth headers, verify user permissions. 403 Forbidden - authenticated but unauthorized. Review scopes and roles. 404 Not Found - resource missing. Check URLs, verify endpoints, correct resource IDs. 429 Too Many Requests - rate limited. Implement retry with exponential backoff, review API limits. 500 Server Error - backend failure. Check server logs, review error messages, notify support teams.
HTTP response categories and best practices
Success responses (200, 201, 204) indicate operations completed as expected. Use appropriate status codes: 200 for GET/PUT, 201 for creation, 204 for DELETE/success without body. Redirection (301, 302, 303) guide clients to new location. 301 permanent, 302 temporary, 303 use proper HTTP methods. Client errors (400, 401, 403, 404) indicate request issues. 4xx responses don't require client retries. Server errors (500, 502, 503) require backend investigation.
RESTful API design and error handling patterns
Implement standardized error responses: JSON with error codes, message, and optional details. Use HTTP status codes correctly with clear semantics. Include request ID headers for debugging. Return proper cache headers for GET responses. Handle idempotent operations safely. Document all status codes and edge cases expected by API consumers. Provide useful error messages in development environments, generic messages in production.