Optimizing Scan Performance

Scan performance optimization begins with proper target selection. Scanning everything discovered by the Spider often proves inefficient. Use Context settings to define which URLs require active scanning. Exclude static resources like images, CSS, and JavaScript files that rarely contain vulnerabilities. Focus on dynamic content accepting user input. This targeted approach reduces scan time while maintaining security coverage.

Parallel scanning dramatically reduces total scan time for large applications. Configure thread pools through Options > Active Scan. More threads enable simultaneous testing of different parameters or pages. However, excessive parallelism can trigger application errors or security controls. Monitor application logs during scanning to identify optimal thread counts. Production scanning typically requires conservative settings to avoid service disruption.

Input vector optimization prevents redundant testing. ZAP can identify similar parameters across different URLs, testing unique vectors rather than every instance. Enable "Optimistic" input vector handling for applications with consistent parameter naming. This optimization particularly benefits REST APIs where the same parameters appear across multiple endpoints. Monitor coverage to ensure optimization doesn't skip important test cases.