Static application security testing analyzes source code or related artifacts for security weaknesses without executing the application.
Static application security testing, or SAST, analyzes source code or related build artifacts for security weaknesses without running the application. In plain language, it looks at the code structure itself to find patterns that may lead to insecure behavior.
SAST matters because it can find issues early in the development lifecycle, often before software reaches production or even full runtime testing. Catching flaws earlier usually makes fixes easier and cheaper.
It also matters because code-level analysis can highlight risky patterns that may not be obvious from external behavior alone. This supports more disciplined secure-development workflows.
SAST appears in CI pipelines, pull-request review, secure-development programs, and application-governance requirements. Teams use it to scan code for risky constructs, common vulnerability patterns, or insecure usage of libraries and frameworks.
Security teams compare SAST with Dynamic Application Security Testing because the two approaches answer different questions: one inspects code structure, while the other inspects running behavior.
A development team submits new code for a customer portal. Before merge, the CI pipeline runs SAST and flags a database query pattern that may allow SQL Injection. The team fixes the query construction before the change is released.
SAST is not the same as DAST. SAST does not exercise the running application from the outside. It analyzes code or related artifacts directly.
It is also not a substitute for secure engineering judgment. SAST findings need review, prioritization, and developer understanding to become meaningful improvements rather than noise.