Non-functional testing is testing software for its non-functional requirements: the way a system operates, rather than specific behaviors of that system. This is in contrast to functional testing, which tests against functional requirements that describe the functions of a system and its components.

Non-functional testing includes:

• Accessibility testing
• Baseline testing
• Compliance testing
• Documentation testing
• Endurance testing or reliability testing
• Load testing
• Localization testing and Internationalization testing
• Performance testing
• Recovery testing
• Resilience testing
• Security testing
• Scalability testing
• Stress testing
• Usability testing
• Volume testing