Regression Testing: An In-Depth Guide for 2026

March 4, 2026 · Male Ibarra James · Updated April 6, 2026

With constant software updates, regression testing is more critical than ever.

Skip ahead to:

  1. What is regression testing?
  2. Why should you do regression testing?
  3. How frequently should you run your regression tests?
  4. What is the difference between retesting and regression testing?
  5. How to prioritize and select regression tests
  6. Manual vs automated regression testing
  7. How to do regression testing manually
  8. How to do automated regression testing: best practices
  9. The benefits of automated regression testing
  10. How to choose regression testing tools: the main criteria
  11. Best regression testing tools: Top 8 list

What is regression testing?

The verb regress (from regression testing) means to return to a former state or condition. Regression testing is a vital component in the testing lifecycle, whether you are checking simple web application functionality or complex, end-to-end business workflows. It safeguards your applications and processes against bugs as they evolve over time. This is because every software update requires testing to ensure that things do not break.<

Simply put, there are two sides of testing:

  1. Testing new features
  2. Testing existing functionality

Regression testing focuses on the latter. It is the process of testing existing functionality when new code alterations are made. Every now and then, however, updates can go wrong and cause disruptions to the user experience.

Regression testing ensures that the new modifications work as intended and that previous functionality remains intact and bug-free. These tests are usually performed frequently and consistently, acting as a safety net to quickly identify and rectify regressions before they affect production.

Watch this snippet from our Regression Testing Webinar to hear how our experts explain it in simple terms: