A/B Test Significance Calculator
Objective: Evaluate A/B test results to determine whether a conversion-rate difference is statistically significant.
Ready for a readout
Enter visitors and conversions for each variant, then calculate the result.
Methodology
Significance uses a two-proportion, two-tailed z-test. Error bars and shaded chart bands use 95% Wilson confidence intervals. The curves use beta distributions to visualize plausible conversion-rate ranges for each variant.
v0.1.23 · Updated Apr 18, 2026