Have you ever worried that a new update might unintentionally break your software? Regression testing is your safety net to keep your app running smoothly, here’s everything you need to know.

As businesses roll out frequent software enhancements, regression testing becomes vital to maintaining stability and user trust.

Studies show that around 69% of software failures are due to poorly managed updates, emphasizing why thorough regression testing is essential for stable releases

But here’s the catch: while regression testing helps ensure nothing breaks after changes, it can also be  time-consuming and prone to mistakes if not handled properly.

This guide will take you through the basics of regression testing:

• What regression testing really is (and isn’t)
• How automation can make it faster and more reliable
• The benefits it brings to speed and quality
• The top tools that can make your team’s job easier

By the end, you’ll see how regression testing can help your QA team  achieve high test coverage and deliver smooth releases every time, no matter how often updates are pushed out.

What is Regression Testing?

The word regress means “to go back to an earlier state.” In software, regression testing makes sure that when new updates or changes are made, the existing features still work the way they should.

Why should you do regression testing?

Imagine you’re running a popular food delivery app. One day, your team adds a new feature that lets users track their orders in real-time. Exciting, right? But after the update, some users start facing issues with placing orders. Oops!

This is where regression testing comes in. It’s like having a safety net for your software. Every time you make a change, whether it is big or small, you go back and check the existing features to make sure nothing else broke.

Why does it matter? Because fixing a bug before it reaches your users is way cheaper and easier than cleaning up a mess in production. By catching problems early, regression testing helps keep your app reliable, your users happy, and your team’s work stress-free.

How Often Should You Run Regression Tests?

Just Think of your software like a busy highway. Every time you make changes, add a new lane, fix a pothole, or change a traffic signal, you want to make sure the rest of the road still works smoothly. That’s why regression tests should run every time the code changes.

For small apps, you can do it manually. However, for big, complex systems, running the full regression suite manually is like checking every road in a city on foot; it’s slow and exhausting. That’s where Test automation comes to the rescue, running tests quickly and reliably.

Retesting vs. Regression Testing

It’s easy to get confused because they sound similar, but they have a key difference:

• Regression Testing: Checks for unexpected problems caused by recent changes. It’s like a safety check to make sure nothing else broke.
• Retesting: Focuses on the specific bugs you already know about. It’s like double-checking that a bug you fixed really stays fixed.

What is Retesting?

Retesting (also called confirmation testing) is when you check again to make sure a specific problem you found is actually fixed. You’re not looking for new problems, just confirming that the bug is gone.

Example: Imagine you fixed a login bug. Retesting would mean logging in repeatedly to confirm the bug is gone. Regression testing, on the other hand, would check the login, signup, payment, and other features too, making sure nothing else broke while you were fixing the login bug.

How to Pick the Right Regression Tests

Once you’re ready to build your regression test suite, the next step is deciding which tests to run first. You can’t test everything every time, so it’s important to focus on what matters most. Here are some simple guidelines:

1. Test Core Features First

Ask yourself: Is this function essential for the product? Does other functionality depend on it? Core features should always be tested because if they break, it affects the whole app.

2. Prioritize New Features

New code is more likely to have bugs. Make sure recently added features are thoroughly tested, especially if they interact with other parts of the system.

3. Check Environment-Sensitive Code

Some code depends heavily on specific settings or configurations. These areas are more prone to errors, so give them extra attention.

4. Focus on Previously Problematic Code

Code that has caused issues in the past is likely to fail again. Always include these in your regression tests to prevent repeated bugs.

Manual vs automated regression testing

Automation is powerful, but it can’t fully replace human judgment. Some parts of testing need a real person’s eyes, creativity, and intuition. Other parts are repetitive and time-consuming, that is perfect for automation. The table shows which tests fit best for manual vs. automated regression testing, but the way you carry them out is different.

Tests Best Suited for Manual Regression Testing	Tests Best Suited for Automated regression Testing
Exploratory testing – testers freely explore the app to uncover unexpected issues.	Repetitive tests – tasks that need to be run repeatedly across releases.
Human judgment areas – checking design, usability, and overall user experience.	Data-driven tests – the same actions tested with multiple sets of data.
New features – freshly developed or changing features are better tested manually at first.	Performance & load tests – automation can simulate thousands of users to check speed and stability.
Complex user interactions – tricky actions (like drag-and-drop with precise timing) are often easier manually.	Stable features – areas of the app that don’t change often are perfect for automation.
	Smoke & sanity tests – quick checks after a new build to confirm key functions are working.

How to Do Regression Testing Manually

Manual regression testing means real people (often business users or QA testers) go through the application step by step to make sure everything still works after changes. It’s slower and can be tiring, but it’s still valuable, especially when human judgment is needed. Here’s how it works:

Step 1: Understand the Changes

Start by reviewing what’s new, like bug fixes, feature updates, or changes in the system. Then, think about which parts of the application these changes might affect. This “impact analysis” helps you know where to focus your testing.

Step 2: Pick the Right Test Cases

Look at your existing test cases and choose the ones most relevant to the changes. Always include critical features like login, payments, or core workflows. If new features were added, write new test cases to cover them.

Step 3: Prioritize What to Test First

Since you can’t test everything manually, focus on the most important areas:

• Features directly impacted by the changes
• High-risk or business-critical areas
• Functions that users rely on the most

For small updates, a quick “light” regression may be enough. For big releases, go deeper and test more thoroughly.

Step 4: Run the Tests

Now execute the chosen test cases carefully. Follow the steps, watch how the system behaves, and compare results against expectations. If something looks off, document it with notes, screenshots, or logs so developers can fix it quickly.

Below is an example of how regression test cases can be documented in an Excel sheet. Each row represents a test case with details such as the module, description, preconditions, and steps. On the right, you’ll see the actual result, expected result, and test labels (e.g., regression, retesting).

This structured format makes it easier for teams to track progress, identify failed cases quickly, and maintain a clear history of test execution.

Step 5: Log Defects

If you spot a bug during testing, record it clearly. Give developers all the details they need, like what went wrong, how to reproduce it, and screenshots or logs. Once they fix the issue, test it again in the next regression cycle to make sure the fix didn’t break something else.

Step 6: Keep Improving

Don’t just run the same tests repeatedly, learn from them. Look for patterns, like features that fail often, and adjust your testing strategy to focus on those weak spots. Also, keep your test suite fresh by adding cases for new features and removing outdated ones.

Step 7: Collaborate with the Team

Manual regression testing works best when testers, developers, and business analysts all communicate openly. Share your test results, highlight any serious issues, and make sure everyone is on the same page about the quality of the release.

Best Practices for Automated Regression Testing

Automated regression testing helps teams save time, increase accuracy, and speed up release cycles. But to make it work well, you need the right strategy. Here are some best practices to follow:

1. Start with the Right Test Cases

Not every test should be automated. Focus on:

• Repetitive test cases you run every release
• Critical business workflows (like login, checkout, payments)
• Stable features that don’t change often
• Data-driven tests that need to be repeated with multiple inputs

2. Keep Your Tests Maintainable

Applications evolve, and so should your test scripts. Write tests that are modular and easy to update, so when changes happen, you don’t have to rewrite everything.

3. Integrate with CI/CD Pipelines

Connect your automated regression suite to your Continuous Integration/Continuous Delivery (CI/CD) pipeline. This way, tests run automatically whenever new code is committed, giving developers quick feedback and reducing risks.

4. Use the Right Tools

Pick automation tools that:

• Support your application type (web, mobile, API, desktop)
• Fit your team’s skillset
• Provide good reporting and integration options

Popular tools include Selenium, Playwright, Katalon , and Cypress.

5. Monitor Test Results Regularly

Automation doesn’t mean “set it and forget it.” Review reports, track failure trends, and investigate flaky tests (tests that sometimes pass, sometimes fail) to keep your suite reliable.

6. Combine Automation with Manual Testing

Automation is great for speed, but it can’t judge usability, design, or user experience. Balance automation with manual testing for areas that need human insight.

7. Continuously Improve Your Suite

Regularly clean up your automated test suite. Remove outdated scripts, add new ones for new features, and optimize execution time so tests stay effective and efficient.

Automated Regression Test Script Example

The screenshot below shows a Python script using Selenium and  Pytest. It automates key flows like signup and payment, with assertions to verify expected results. Such scripts make regression testing faster, repeatable, and less error-prone compared to manual testing.

Benefits of Automated Regression Testing

Regression testing is all about making sure that when new updates, features, or fixes are added, nothing else in the software breaks. It’s like doing a quick check-up after every change to confirm everything still works smoothly. Here are the biggest advantages of regression testing:

Better Test Coverage

Regression testing allows you to cover more parts of the software by running old test cases again. This ensures that both the new features and existing ones are working properly. As a result, the overall test coverage improves, reducing the risk of missing bugs.

Quick Feedback

Whenever code changes are made, regression tests provide immediate feedback on whether something broke. This helps developers catch problems early, before they become bigger and more expensive to fix.

Saves Cost and Time

Finding bugs early means you avoid costly fixes later in the development cycle. Plus, automating regression tests save time by reducing repetitive manual work, freeing up testers to focus on more complex scenarios.

Improves Code Quality

By consistently checking that old features still work with new updates, regression testing helps maintain clean, reliable code. This makes the system more stable and easier to maintain in the long run.

Supports Scalability

As your software grows, regression testing ensures that new features don’t negatively affect existing ones. This makes it easier to scale your application without worrying about breaking old functionality.

Frequent Testing

Instead of waiting until the very end of the development cycle, regression tests can be run regularly. This frequent testing means issues are spotted and fixed faster, keeping quality high throughout the process.

Reduced Maintenance Effort

Automated regression testing reduces the need for repetitive manual testing. Once test cases are created, they can be reused across builds, which saves time and makes test maintenance easier.

Better Traceability

Every time regression tests are run, the results provide a clear record of what was tested and what changed. This makes it easier to track updates, increases transparency, and ensures accountability across the team.

24/7 Testing

Automation allows regression tests to run at any time, even overnight or during weekends. This means faster results and more efficient use of time while developers and testers focus on building new features.

How to Choose Regression Testing Tools: Key Things to Look At

Picking the right regression testing tool isn’t just about going with the most popular one. You need to look at a few important factors before making a decision:

Getting Started (Ramp-up)

• Ease of use – Is the tool simple enough for testers who may not be very technical? A user-friendly tool saves time and frustration.
• Ramp-up time – How quickly can your team learn and start using it effectively? The faster, the better.
  

Growing with the Team (Scaling up)

• Collaboration – Can multiple team members work together easily in the tool?
• Support – Does the vendor provide strong customer support, especially if your team works across different time zones?
• Maintenance – Will the tool need a lot of upkeep and updates, or is it relatively low-maintenance?

Covering All Needs (End-to-End Capabilities)

• Application support – Does the tool work across different platforms, browsers, and technologies? A versatile tool means you don’t have to juggle multiple tools for different apps.

Real-World Proof (User Reviews)

We also checked G2 user reviews and ratings to see what actual testers and QA teams had to say about these tools. Real feedback helps confirm whether a tool delivers on its promises.

Key Takeaways

• Regression testing safeguards your software by catching unexpected bugs after changes.
• Automation speeds things up, handling repetitive tests, while manual testing adds human judgment for tricky issues.
• Always prioritize core functions and new features, they’re the most likely to break and the most critical for users.
• Pick the right tools that match your team’s skills and your application’s needs.
• Keep your test suite fresh with regular reviews and maintenance so it stays effective over time.

FAQs

Can regression testing be done manually?

Yes, regression testing can be done manually. Testers run selected test cases step by step to check if recent changes have broken existing features. However, for large or complex applications, manual regression testing can be very time-consuming. That’s why many teams use test automation to handle repetitive checks while keeping manual testing for areas that need human judgment, like user experience.

Why is regression testing important?

Regression testing is important because it ensures that new changes, like bug fixes, updates, or new features, don’t break what was already working. Without it, even small changes could introduce hidden bugs that may impact the user experience or system stability.

When should regression testing be performed?

Regression testing should be performed every time the code changes, whether it’s a bug fix, an update, or a new feature. In agile or CI/CD environments, regression testing is often automated and runs frequently (sometimes even daily) to give fast feedback.

What does regression testing mean?

Regression testing means re-running tests on an application to check if existing features still work correctly after changes have been made. In simple words: it’s making sure that fixing one thing doesn’t break something else.

 Who does regression testing?

Regression testing is usually done by the QA team, but in agile teams, developers and testers often share the responsibility. Testers typically design and run the regression suite, while developers may also run automated regression tests as part of the build process.