AI A/B Test Designer
Describe what you want to learn and Growth Prophet's AI designs a rigorous A/B test — hypothesis, variants, sample size, and success metrics — so every experiment reaches a clear decision.
Shipping a change and "seeing if it helps" feels like experimentation but usually isn't — without a defined metric and enough sample, you're reading random noise and calling it a result. Real A/B testing is what separates changes that actually moved the needle from changes you just happened to ship in a good week.
Growth Prophet designs the test properly before you run it. It turns your question into a clear hypothesis, defines the control and variant, names the primary success metric and the guardrail metrics that protect against unintended damage, and calculates the sample size and runtime you need from your baseline rate and the smallest effect worth detecting. The result is an experiment that reaches a trustworthy yes-or-no, not an inconclusive shrug.
How to design an A/B test
- Describe what you want to learn — State the change or question you're testing.
- Get a rigorous design — The AI defines the hypothesis, control and variant, primary and guardrail metrics.
- Run to significance — Use the recommended sample size and runtime so the result is real, not noise.
Frequently asked questions
What does the A/B test designer produce?
It turns a question into a runnable experiment: a clear hypothesis, the control and variant definitions, the primary success metric and guardrail metrics, and the sample size and runtime you need to reach a statistically meaningful result.
How does it calculate sample size?
Based on your baseline conversion rate and the minimum improvement you'd care about (the minimum detectable effect), the tool estimates how many users per variant and how long you should run the test to detect that effect with standard statistical confidence.
Why design a test instead of just trying a change?
A structured A/B test isolates the impact of one change and tells you whether the result is real or noise. Without a defined hypothesis, metric, and sample size, you risk shipping changes based on random variation. The designer enforces that rigor so every experiment reaches a clear yes/no decision.
Is the A/B test designer free?
You can start on the Free plan with no credit card required. Growth Prophet is free to start — no credit card required. Paid plans are Pro at $19/month and Max at $29/month, both with a 14-day money-back guarantee.