​​Regression testing—when done well—gives software teams the confidence that their entire application works properly after a code change. But doing regression testing manually is time-consuming, costly, and difficult to scale. As their applications grow in complexity, many teams end up having to throw more and more resources into regression testing—hiring more QA specialists and waiting longer for them to complete testing with each release cycle.

The testing landscape has changed over time to include automated and functional testing as the baseline, but there are still ways to improve your testing because even with a fully automated continuous testing pipeline, there can still be the possibility of bugs existing in your passing tests. One of the ways to mitigate this is by adding visual testing to your testing pipeline.

Automated visual regression testing tools check for style issues and problems with the visual layer of an app or website. The benefit of these tools is that they can catch issues on the visual layer (the user interface of the website or app, which customers see) that may get missed by test scripts that only interact with the underlying code (the DOM).

For teams following agile software development practices, regression testing is a must. Agile teams constantly make changes to live software that can introduce regressions (or, code changes that break the functionality of part of an app). Regression testing can keep teams from shipping critical bugs to production by confirming the most important parts of an app are still working every time new code is pushed.

Regression Testing, as all Quality Assurance professionals know, is ensuring that previously developed and tested software continues to operate after a change. Performance Regression being a subset of regression testing as a discipline is therefore ensuring that previously developed and tested continues to meet its performance criteria after a change.