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A/B Test Significance
Two-proportion z-test for conversion experiments
Runs locally in your browser
Parameters
Results
- Lift
- 16%
- Control rate
- 5%
- Variant rate
- 5.8%
- Z-score
- 1.77
- Confidence (approx)
- ≈ 90%
Approximate two-proportion z-test. For small samples or extreme rates, use a proper stats package.
How it works
Runs an approximate two-proportion z-test on control vs variant conversion rates.
Who it's for: Growth and product teams deciding whether an A/B test won.
Computes lift, rates, z-score, and approximate confidence band.
Uses a pooled standard error for the difference of proportions.
How to use
- Enter visitors and conversions for Control and Variant.
- Treat ≥95% confidence (≈ |z| ≥ 1.96) as a common decision threshold.
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