A/B Test Significance Lite
Compare two conversion rates with a lightweight z-test estimate for experiment planning.
Check whether an A/B test is probably meaningful
A/B tests can show noisy differences that look exciting but do not hold up. A quick significance check helps separate obvious random variation from a result that may deserve more attention.
It runs a lightweight z-test to estimate whether two conversion rates differ beyond chance — enough to sanity-check an experiment, though a full statistics tool is better for high-stakes calls.
Enter visitors and conversions for variants A and B. The calculator returns conversion rates, uplift, z-score, and an approximate confidence estimate. Use it as a planning aid, not a final statistical authority.
Private planning math
Experiment data stays in your browser. No analytics or conversion counts are uploaded.
Frequently Asked Questions
Is this a full statistics suite?
No. It is a lightweight two-proportion z-test estimate for quick experiment checks.
What inputs do I need?
Enter visitors and conversions for each variant.
Should I stop a test only from this?
No. Consider sample size, test duration, data quality, and business impact before deciding.
Is this private?
Yes. It runs locally in your browser.
Need sharper pricing, projections, or growth planning? Let us help.