SAST vs DAST vs SCA: What’s the Difference and When to Use Each

SAST vs DAST vs SCA: What’s the Difference and When to Use Each Introduction Application security testing isn’t one-size-fits-all. Modern software systems contain multiple layers of risk — from insecure code and vulnerable dependencies to runtime misconfigurations. Three major testing approaches dominate modern application security: SAST (Static Application Security Testing) DAST (Dynamic Application Security Testing) SCA (Software Composition Analysis) Each method detects different types of vulnerabilities at different stages of the development lifecycle. Relying on only one approach leaves security gaps. This guide explains the differences between SAST, DAST, and SCA , when to use each method, and how combining them improves application security. What is SAST? Static Application Security Testing (SAST) analyzes application source code, bytecode, or compiled binaries without executing the application. Instead of interacting with a running system, SAST tools review the code itself. The