3xx Status Codes Explained: 301, 302, 303, 307, 308
What a 3xx status code means, how 301, 302, 303, 307 and 308 differ, and how to monitor redirect chains — HTTP redirects, not a game.
5xx Server Errors: 500, 502, 503, 504 Explained
Understand 500, 502, 503 and 504 server errors, diagnose application, proxy and upstream causes, and monitor status, body and error-rate patterns.
Response Body Validation: Detect False 200 OK
Validate required HTML, JSON fields, schemas and negative error markers so status-only monitors catch false-green pages, APIs and login redirects.
HTTP Status Codes Explained: 1xx, 2xx, 3xx, 4xx, 5xx
Understand HTTP status code classes and common codes, then configure monitoring that validates expected success, redirects, client errors and server failures.