FREE TOOL

Know if your test actually has a winner.

Enter visitors and conversions for two variants to get lift, confidence, and a clear verdict. Free, no signup, runs in your browser.

Enter your test results

Visitors or impressions both work, just stay consistent.

Variant A, control

Variant B, challenger

Verdict97.7%Variant B winsSignificant at the 95% confidence level, p = 0.023.
Conversion rate A2.31%Conversions divided by visitors for A.
Conversion rate B3.12%Conversions divided by visitors for B.
Relative lift+35.2%Change in conversion rate, B against A.
p-value0.023Two-sided, from the pooled z-test.
Chance B beats A98.9%One-sided probability B truly converts better.

The test told you which angle won. It cannot tell you what to test next.

Adlicio scrapes real comments and reviews from Reddit, YouTube, Amazon and more, then ranks the pains, objections, and hooks your buyers respond to. Your next five variants are already in their words.

01Field guide

How to call an A/B test

An A/B test is only as good as the discipline around it. Test one variable at a time, the hook, the thumbnail, the offer, never two at once, or the result cannot tell you what worked. Decide the confidence threshold before the test starts and let the data reach it. The most common testing mistake is calling a winner in the first two days because one variant jumped ahead, which is exactly what random noise looks like.

Read the three numbers together. Relative lift is the size of the prize, how much better B converts than A. The p-value is the reliability of that prize, the chance you would see a gap this big from noise alone. A huge lift with a weak p-value is a rumor, not a result. And the chance-B-beats-A number is the one-sided read: useful for a leaning, not a substitute for significance.

Sample size does the heavy lifting. Two conversion rates a few tenths of a point apart can take thousands of visitors per variant to separate, so budget the traffic before you launch, and treat anything under about 30 total conversions as directional. If a test will not reach a useful sample in two weeks, test a bigger swing, a different hook angle rather than a comma.

Significance tells you which angle won. It cannot tell you what to test next. That comes from your customers, and the fastest way to hear them is scraping real comments into ranked angles and objections. See pricing for what Adlicio unlocks.

02FAQ

A/B test significance FAQ

What does statistical significance mean in ad testing?

Statistical significance is the point where the gap between two variants is unlikely to be random noise. In practice you compare the p-value to a threshold, usually 0.05. A p-value below it means there is less than a 5% chance you would see a difference this large if the variants truly performed the same, so you can call a winner with reasonable confidence instead of reading tea leaves.

How does this A/B test significance calculator work?

It runs a two-proportion z-test, the standard test for comparing two conversion rates. It pools both variants to estimate a shared standard error, computes a z-score for the gap between the rates, and converts that into a two-sided p-value. Below 0.05 the result is significant at 95% confidence. Everything runs in your browser, nothing is sent to a server.

How many conversions do I need for a reliable A/B test?

There is no single magic number, but most practitioners want at least 100 conversions per variant before trusting a result, and more when the two rates are close together. Below roughly 30 total conversions this calculator flags the verdict as directional. The smaller the true difference between variants, the more data it takes to separate it from noise.

Should I use 90% or 95% confidence for ad creative tests?

95% is the standard and it is what this calculator uses for its verdict. Some ad buyers accept 90% for creative tests because traffic is expensive and a wrong call is cheap to reverse, you simply test again. The tradeoff is simple: a lower bar calls tests faster but is wrong more often. Whichever threshold you pick, commit to it before the test starts, not after peeking at the numbers.

Is this A/B test significance calculator free?

Yes. It runs entirely in your browser, so there is no signup, no credit card, and nothing is sent to a server. Enter visitors and conversions for each variant and the verdict, lift, p-value, and confidence update instantly.
FROM VERDICT TO NEXT TEST

You called the winner. Now find the next angle worth testing.

Try Adlicio free. Adlicio scrapes real comments and reviews into ranked angles and hooks, so your next variants start from what buyers actually said.

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Angle auditWhat your first brief should decide
Input

product URL, competitor, or keyword

Buyer repeat
pain stack
Belief gap
objection map
First test
hook + brief
Output3 angles, 10 hooks, 1 shippable brief