Chapter 4 – Test Techniques
Differential Testing – ISTQB Definition
Last Updated: July 12, 2026 · SoftwareTestPilot QA Team
Official ISTQB Definition
A technique that runs two implementations of the same feature against identical inputs and flags differences in output.
In simple words
Comparing two versions of the same thing against the same inputs and catching where they disagree.
Exam tip
Common when replacing a legacy system — run old and new in parallel and diff outputs.
Related terms
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