Edge blocking is the practice of stopping malicious requests at the delivery layer, such as a CDN, reverse proxy, API gateway, or web application firewall, before they reach the application itself. It is a front-line control that filters traffic close to where it enters the environment, rather than waiting for the backend service to process it.
This matters because the earlier abusive traffic is rejected, the less load, risk, and attack surface the application has to absorb. Edge blocking is commonly used against bot abuse, credential stuffing, injection probes, and exploit attempts that can be recognized from request patterns, IP reputation, headers, or malformed payloads. In defense, it often complements runtime tools and internal controls: the edge can drop obvious hostile traffic, while deeper inspection handles attacks that only become clear once the application logic starts running.