Free tool
Experiment significance calculator
Find out whether the difference between your control and test is real or just noise. Works for A/B tests on conversion rates and on averages such as revenue per visitor.
Metric type
Confidence level
Hypothesis
Variant A (control)
Variant B (test)
Enter the numbers for both variants to see your result.
Decide sample size and duration before you start, and don't stop the test the moment it turns significant. Repeated peeking inflates false positives.
Need help running experiments?