# What Is Regression Testing?

## Definition

Regression testing reruns tests to look for unintended changes in previously expected behavior after the application changes.

## Why it matters

A shared component or dependency update can affect flows outside the feature being edited. A reviewed regression suite makes those expectations explicit.

## How teams handle it today

Teams keep stable fixtures, update tests when requirements change and investigate failures before accepting a new baseline. They avoid expanding the suite with redundant cases nobody reviews.

## How Zerocheck approaches it

Save browser tests in Zerocheck and rerun one, selected tests or all tests against a configured environment. Each run keeps the exact YAML revision, screenshots and step outcomes, so the team can inspect whether a regression actually occurred.

Related terms: [E2E Testing](https://tryzerocheck.com/glossary/e2e-testing/), [Test Automation](https://tryzerocheck.com/glossary/test-automation/), [Flaky Test](https://tryzerocheck.com/glossary/flaky-test/)


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Canonical: https://tryzerocheck.com/glossary/regression-testing/
Updated: 2026-09-14