What is Verification vs Validation?

Verification asks "are we building the product right?", checking work against its specifications, while validation asks "are we building the right product?", checking that it actually meets user needs. Verification is about conformance to spec; validation is about fitness for purpose.

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IN DEPTH

In depth.

The two terms are easy to recite and easy to confuse, which is why interviewers love the question. Verification confirms that each stage of development matches the agreed requirements and design. It is largely static, reviews, walkthroughs, and inspections of requirements, designs, and code, and it happens throughout development. The classic phrasing is "are we building it right?": does the work conform to the spec?

Validation confirms that the finished (or near-finished) product actually solves the user's problem. It is largely dynamic, executing the software through functional, system, acceptance, and usability testing, and it answers "are we building the right thing?": does it meet real needs, even if the spec itself was wrong?

The nightmare case shows why you need both: a team can verify perfectly (the product matches the spec exactly) and still fail validation (the spec described the wrong product, so users hate it). Verification catches defects against the spec early and cheaply; validation catches the deeper risk that the spec was wrong.

WHY IT MATTERS

Why interviewers ask about this.

Verification vs validation is one of the most common QA interview questions. A crisp answer, are we building it right (verification) vs are we building the right thing (validation), with an example of passing one and failing the other, signals solid fundamentals.

EXAMPLE

Example scenario.

A team builds a report feature exactly as the spec described, every field, every format, verification passes. But validation with real users reveals the report answers a question nobody asks; the spec was wrong. The product was built right but was not the right product.

TIP

Interview tip.

Memorize the two phrasings (build it right vs build the right thing) and map them: verification is static, against the spec, throughout development; validation is dynamic, against user needs, near the end. The "verified but not validated" example seals the answer.

FAQ

Frequently asked questions.

What is an easy way to remember verification vs validation?

Verification is "are we building it right?" (conformance to spec, mostly static reviews). Validation is "are we building the right thing?" (fitness for user needs, mostly dynamic testing). You can verify a product perfectly and still fail validation if the spec was wrong.

Is verification static or dynamic?

Verification is largely static, reviews, walkthroughs, and inspections of requirements, designs, and code, done throughout development. Validation is largely dynamic, executing the software to confirm it meets user needs.