Free A/B Test Significance Calculator.

Use this A/B test significance calculator to estimate conversion lift and two-sided statistical confidence. Get the observed lift, confidence level and a significance verdict.

The result gives you a clear snapshot to review and discuss.

Run it with current information and revisit it after meaningful changes.

Check your A/B test result

Compare two conversion rates with a two-sided pooled z-test.

Experiment data

1 / 2

Control
Unique eligible visitors exposed to the control.
Control visitors who completed the target action.

Why it matters

Why a A/B test significance calculator matters.

The visitor and conversion totals from your control and variant can affect discoverability, visitor experience and the quality of decisions made by marketing teams. Small issues are easy to overlook when evidence is spread across pages, tools or assumptions.

A A/B test significance calculator creates one repeatable place to estimate conversion lift and two-sided statistical confidence. The result helps separate urgent problems from acceptable choices and gives collaborators a concrete starting point for discussion.

Regular checks are most useful when the same inputs and expectations are applied over time. Record important changes, validate the result in context and combine this snapshot with broader business evidence.

Fast review

Review the visitor and conversion totals from your control and variant without a lengthy manual process.

Clear evidence

Use a concrete result instead of relying on assumptions.

Practical next step

Identify what deserves attention before making wider changes.

Repeatable process

Run the same check again as your website evolves.

How to use

Use the A/B test significance calculator in three steps.

Provide current information, run the tool, then review the result in its wider context.

  1. Add your input

    Enter complete, current information and check it carefully for obvious mistakes before continuing.

  2. Run the tool

    Submit the form so the A/B test significance calculator can apply one clear, consistent method to every input.

  3. Review the result

    Validate important findings in their wider context and prioritise the next useful action for your team.

FAQs

A/B Test Significance Calculator FAQ

Practical answers about A/B test confidence, lift and statistical significance.

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