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Regression Testing vs Retesting: What's the Difference?
Virtuoso QA
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Regression testing and retesting sound alike, but they do very different jobs. Retesting checks that a specific defect has been fixed. Regression testing checks that the fix didn't break anything else. Mixing them up leads to incomplete testing, escaped defects and wasted effort, so it's worth knowing exactly when to use each.
The Defect Resolution Challenge
A tester finds a bug. A developer fixes it. What happens next?
This is the moment where many teams go wrong. Some confirm the fix and stop, without checking for side effects. Others run their full test suite but never confirm the original bug is actually gone.
Take a real scenario. A customer reports that a discount code is giving the wrong amount off at checkout. The team finds a calculation error and ships a fix. Now what?
If QA only checks that the discount code now works, they've retested. The fix is confirmed. But what if the change also affected shipping costs, VAT or the order total shown in confirmation emails? Those problems reach customers, because nobody looked.
If QA only runs the general regression suite, without specifically checking the discount fix, they've done regression testing. Side effects are covered. But what if the fix only worked for some carts, and the original bug still happens in others? The defect stays unresolved, because nobody checked it directly.
Good QA needs both. Retesting confirms the fix works. Regression testing confirms the fix didn't break anything else. Skip either one and defects get through.
What is Retesting in Software Testing?
Retesting, also called confirmation testing or defect verification, checks that a specific reported defect has been fixed. It answers one question: does this bug still happen?
Retesting is narrow and targeted. The tester repeats the exact steps that produced the defect. If the defect is gone, the retest passes. If it's still there, the retest fails and the issue goes back to development.
Core Characteristics of Retesting
Specific to one defect: Each retest covers a single defect, and its scope is set by the defect report.
Depends on clear reproduction steps: Retesting follows the steps, inputs and expected results in the original report. A vague report makes retesting difficult, sometimes impossible.
A clear pass or fail: The defect is either fixed or it isn't. There's no partial credit.
Triggered by the developer: Retesting starts when a developer marks a defect as fixed and hands it back for confirmation.
How Retesting Works
The developer marks the defect as fixed and deploys it to the test environment.
The tester opens the defect report and its reproduction steps.
The tester sets up the required preconditions and test data.
The tester repeats the exact steps from the report.
The tester compares the actual result with the expected one.
If the defect is gone, the tester marks it verified and closes it.
If the defect is still there, the tester marks the retest failed and sends it back to development.
Retesting Example: A Discount Calculation Fix
Original defect report
Title: Discount code SAVE20 includes shipping in the discount calculation
Steps to reproduce:
Add an item priced at £100 to the cart.
Go to checkout and choose standard delivery (£10).
Apply the discount code SAVE20.
Check the discount amount.
Expected result: The discount is 20% of the item subtotal only, so £20.00 off. The order total is £90.00.
Actual result: The discount is 20% of the subtotal plus shipping, so £22.00 off. The order total is £88.00.
Retest
Once the fix is deployed, the tester repeats the same four steps. If the discount now shows £20.00 and the total is £90.00, the retest passes. If it still shows £22.00, or any other wrong amount, the retest fails.
During the retest, the tester checks nothing else. Not other discount codes, not other delivery options, not the rest of checkout. Retesting is only about this one defect.
What is Regression Testing
Regression testing checks that recent code changes haven't harmed existing functionality. It answers a different question: did this change break anything else?
Regression testing is broad and systematic. It deliberately covers more than the change itself, because a fix that solves one problem can easily cause another in a related, or completely unrelated, part of the application.
Core Characteristics of Regression Testing
Triggered by any change: Not just bug fixes. New features, enhancements, refactoring, infrastructure changes and dependency updates all need regression testing.
Covers more than the change: A discount fix could affect shipping, VAT, order totals, receipts and reports, and regression testing checks all of them.
Builds up over time: Regression suites cover all existing functionality, not just the latest change. Over time, they grow to cover the whole application.
Prioritised by risk: Full regression takes time, so teams focus on the highest-risk areas first and sample or rotate coverage elsewhere.
How Regression Testing Works
A code change is deployed to the test environment.
The team identifies which areas the change could affect, and how risky each one is.
The team runs regression tests for the affected areas.
The team runs a broader regression suite, depending on time and risk.
Any failures are investigated, to separate real defects from test problems.
Genuine regressions go back to development to fix.
Each regression fix then needs its own retest, plus another round of regression testing.
Regression Testing Example
After the discount fix is deployed, regression testing covers areas like:
Other discount types, including percentage, fixed amount and free delivery
Stacked discounts, where more than one code is applied
VAT calculations across different product types
Shipping costs, with and without discounts
The order total on the checkout page
The order total in the confirmation email
The order total in order history
Revenue reporting
Refunds for orders that used a discount
Any of these could be affected by a change to the discount logic. Regression testing confirms they all still work.
Key Differences Between Regression Testing and Retesting
Understanding these distinctions enables effective test strategy design.
Aspect | Retesting | Regression Testing |
|---|---|---|
Purpose | Confirms a specific defect is fixed | Confirms changes haven't broken existing features |
Question it answers | "Is this bug gone?" | "Did anything else break?" |
Scope | Narrow, limited to one defect | Broad, covering everything the change could affect |
Trigger | A developer marks a defect as fixed | Any code change at all |
Test case source | The steps in the defect report | The existing regression suite |
How often it runs | Once per fix attempt | Continuously, on every change |
What a failure means | The defect isn't fixed and goes back to development | Something else broke, which is logged as a new defect |
Relationship to the change | Directly checks what the change was meant to fix | Checks what the change wasn't meant to affect |
Purpose
Retesting verifies that a specific defect is fixed. The purpose is confirmation. Did the developer's change resolve the reported issue?
Regression testing verifies that changes did not break existing functionality. The purpose is protection. Did the developer's change inadvertently cause new problems?
Scope
Retesting scope is narrow, limited to the specific defect being verified. One defect, one retest.
Regression testing scope is broad, covering existing functionality that might be affected by changes. Multiple features, multiple test cases.
Trigger
Retesting is triggered by defect resolution. A developer marks a bug as fixed, triggering retest.
Regression testing is triggered by any code change. Bug fixes, new features, refactoring, configuration changes, and infrastructure updates all trigger regression.
Test Case Source
Retesting uses the defect report as its test case. The reproduction steps documented when the defect was found become the retest steps.
Regression testing uses the existing test suite accumulated over the product lifecycle. These tests represent all functionality that has been verified and should continue working.
Execution Frequency
Retesting executes once per defect fix attempt. If the first fix fails retest, the cycle repeats until the defect is genuinely resolved.
Regression testing executes continuously. Every change triggers regression testing. The same regression tests may execute thousands of times over the product lifespan.
Outcome Interpretation
Retesting failure means the defect is not fixed. The issue returns to development for another attempt.
Regression testing failure means existing functionality is broken. This is a new defect, even if related to a recent fix, and enters the defect tracking system as a new issue.
Relationship to Change
Retesting directly relates to the specific change made. The retest verifies the exact behaviour the change intended to modify.
Regression testing indirectly relates to the change. Regression tests verify functionality the change was not intended to affect but might have inadvertently impacted.
Why Both Regression Testing and Retesting Are Necessary
Some teams ask whether they really need both. Couldn't regression testing alone cover it? Couldn't they skip retesting if the regression suite already touches the affected area?
The answer is no. Each one does a job the other can't.
Why Regression Testing Can't Replace Retesting
Regression tests check general behaviour, not the exact scenario that broke. A typical regression test for discounts might look like this:
Apply SAVE20 to a £50 order with no delivery charge.
Check the order total goes down.
That test passes whether or not the shipping bug is fixed, because there's no shipping in the order. It confirms discounts apply, but not that they apply correctly in the case that was actually broken.
Retesting repeats the exact defect scenario, so it catches fixes that were incomplete or that only worked for some carts.
Why Retesting Can't Replace Regression Testing
Retesting confirms the bug is gone, but tells you nothing about the rest of the application. Say the developer fixed the discount by changing a shared pricing function. The retest passes, because discounts are now correct.
But the same function also calculates shipping refunds, and those are now wrong. Without regression testing, that new defect goes straight to production.
The Combined Approach
For every defect fix:
Retest the specific defect to confirm it's resolved.
Run regression tests on related functionality to catch side effects.
Run broader regression based on the risk of the change.
Add the retest to the regression suite, so the same bug can't quietly come back later.
Retesting without regression misses side effects. Regression without retesting misses incomplete fixes. And without step 4, an old bug can return months later with nothing in place to catch it.
Putting Retesting and Regression Testing into Practice
Retesting in Practice
Write structured defect reports
Good retesting depends on clear reproduction steps.
Every report should include preconditions, exact steps, test data, and the expected and actual results.
"Discounts don't work" isn't enough to retest against.
Keep environments consistent
Retest in the same kind of environment where the defect was found. If it happened in staging, retest in staging, because environment differences can produce misleading results.
Retest straight away
Retest as soon as the fix is deployed. If other changes pile up first, a failed retest becomes much harder to trace.
Track status clearly
Move each defect through clear stages, such as Open, Fixed, Retest Pending, Retest Passed, Retest Failed and Closed. That makes the workflow easy to manage and measure.
Regression Testing in Practice
Tier the suite by priority
Priority 1 covers critical functionality that must always work, Priority 2 covers important features, and Priority 3 covers edge cases and lower-risk areas. Run tiers based on time and risk.
Analyse the impact of each change
Work out which areas each change could affect, start regression there, and widen it depending on how big and risky the change is.
Build it into CI/CD
Automated regression tests should run on every commit, or at least on every merge to a protected branch. Manual regression is too slow for modern release cycles.
Keep the suite healthy
Remove obsolete tests, update tests when requirements change, and fix or remove flaky ones. A neglected suite either gives false confidence or gets ignored.
Why Manual Regression Testing Cannot Scale
Manual retesting is manageable, because it happens once per fix. Manual regression testing isn't, because it has to happen constantly and across the whole application.
A full manual regression cycle on a large application can take weeks. Teams releasing daily or weekly simply can't wait that long.
Traditional automation helps, but brings its own problem: every UI change breaks tests, and teams end up spending more time repairing the suite than adding to it.
Eventually, keeping full regression coverage becomes impossible to sustain.
How Virtuoso QA Supports Retesting and Regression Testing
Virtuoso QA brings both sides of defect verification into one platform, with a record of everything that was checked.
Release evidence for every fix
Each run records which requirement every test covers, what happened at every step, and who approved the test. When someone asks whether a fix was verified and what else was checked, the answer is already there.
Tests drafted from your requirements
Touchstone agents read your specs, user stories and Jira tickets, and draft requirements and tests from them, citing the source for each one. A named person approves every requirement before anything is built.
Self-healing you can review
When the UI changes, Virtuoso QA finds each element through its other signals and updates the test. Every repair is logged for your team to accept or reject, so the regression suite keeps running and nothing changes without a record.
Plain English test authoring
Tests are written in plain English, so testers can turn a defect's reproduction steps into an automated retest, then keep it in the regression suite. On the Virtuoso platform, SugarCRM saw 8x faster test creation.
UI, API and database in one test
A single test can apply the discount, check the API response, and confirm the order total stored in the database, catching regressions that single-layer tests miss.
Parallel execution
Tests run in parallel across 2,000+ browser, OS and device combinations, so full regression after every fix becomes practical.
Common Mistakes to Avoid
Mistake | What goes wrong | How to fix it |
|---|---|---|
Treating retesting as enough | Teams retest the defect, see it's fixed and release, missing side effects completely | Make it policy that every defect fix gets both a retest and regression testing |
Assuming regression covers the retest | Teams run the full regression suite but never check the reported defect directly, assuming a green suite means the fix worked | Always retest each defect with its original reproduction steps, as a separate step from regression |
Skipping regression for small fixes | A one-line fix seems too small to cause a regression, so it's released without regression testing | Remember that many bugs are one-line changes too, and run regression testing whatever the size of the change |
Retesting in a different environment | The fix is tested somewhere other than where the defect appeared, which can hide a defect that's still there or create failures that aren't real | Retest in the same type of environment where the defect was found, or document the difference and add extra checks |
Letting the regression suite decay | Tests break as the application changes, flaky tests build up, and results get so noisy that teams stop paying attention | Treat suite maintenance as ongoing work, with reviewable self-healing handling routine repairs while your team stays in control |
Relying on manual regression | Manual regression can't cover enough, often enough, for modern release cycles | Automate regression testing on a platform built to keep tests running as the application changes |
Conclusion
Retesting and regression testing do different but complementary jobs. Retesting confirms a specific defect is fixed. Regression testing confirms the fix didn't break anything else. Quality depends on both.
Understanding the difference isn't the hard part. Doing both well, at scale, is. Manual retesting is manageable, but manual regression isn't, and traditional automation brings a maintenance burden that limits how much you can cover.
With Virtuoso QA's AI-powered regression testing, teams can retest fixes, run full regression in parallel and keep suites healthy with reviewable self-healing, with a clear record of what was tested at every step. The teams that get both right ship with confidence. They know their fixes work, they know nothing else broke, and they catch defects before customers do.
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Frequently Asked Questions
Is retesting the same as confirmation testing?
Should retesting be done before or after regression testing?
How many times should retesting be performed?
Is regression testing necessary for every defect fix?
What is the relationship between sanity testing and retesting?
What documentation is needed for retesting?
