A/B Test

Significance Calculator

Two-proportion z-test
Experiment inputs
Variants
A — Control
B — Treatment
Results update instantly. Uses two-tailed z-test.
Results
CONV. RATE A
15.00%
CONV. RATE B
15.94%
RELATIVE UPLIFT
+6.3%
ABS. DIFF
+0.95pp
P-VALUE
0.024
CONFIDENCE
97.6%
Z-SCORE
2.25
B is the winner Statistically significant at 95% level
Sampling distribution
NORMAL APPROX
Variant A
Variant B
What this means
Variant B converts at a higher rate. The observed uplift is unlikely to be due to random chance alone.
Tip: A p-value below 0.05 (95% confidence) is the typical threshold for declaring a winner in A/B tests.
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