# Zulink

## A/B testing

> Category: Links

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## Pages


### Getting started

- [What is Zulink?](https://docs.zulink.co/getting-started/what-is-zulink)
- [Quickstart](https://docs.zulink.co/getting-started/quickstart)
- [Custom domains](https://docs.zulink.co/getting-started/custom-domains)

### Links

- [Creating links](https://docs.zulink.co/links/creating-links)
- [Targeting](https://docs.zulink.co/links/targeting)
- [A/B testing](https://docs.zulink.co/links/a-b-testing)
- [Link security](https://docs.zulink.co/links/link-security)
- [Social previews](https://docs.zulink.co/links/social-previews)

### Design and analytics

- [OpenGraph Designer](https://docs.zulink.co/design-and-analytics/opengraph-designer)
- [Analytics](https://docs.zulink.co/design-and-analytics/analytics)

### Team and plans

- [Members and invitations](https://docs.zulink.co/team-and-plans/members-and-invitations)
- [Roles and permissions](https://docs.zulink.co/team-and-plans/roles-and-permissions)

### AI agents

- [MCP Server](https://docs.zulink.co/ai-agents/mcp-server)

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# A/B testing

An A/B test sends one share of your visitors to one URL and the rest to another, using a single short link. You keep sharing the same URL everywhere and compare the results afterwards in Analytics.

## Setting it up

On the **A/B Testing** tab of a link, switch the test on and add your URLs:

- Up to four destinations per link, at least two for an active test.
- Every destination needs its own share in percent, and the shares must add up to exactly 100.
- The same URL cannot be used twice in one test.
- Optionally set a **completion date**.

## How visitors are assigned

A visitor is assigned to a variant by the link they opened and by a visitor identifier stored in a cookie on your short domain. The assignment is stable: the same person opening the same link again lands on the same variant, so a returning visitor never sees the page flip. Two different links with the same variants distribute independently of each other.

Because the split is computed per visitor rather than per click, the percentages describe how your audience is divided, not how individual clicks happen to fall. Small samples will not match the percentages exactly.

## The completion date

Once the completion date has passed, the test stops: every visitor goes to the link's normal destination from then on. Nothing is deleted, so the variants and their shares are still on the tab and the test can be restarted by moving the date or clearing it.

Without a completion date the test simply runs until you switch it off.

## What takes precedence

[Targeting rules](https://docs.zulink.co/links/targeting) are evaluated before the test. A visitor matching a country or OS rule goes to that rule's destination and never takes part in the split. If you want everyone in the test, keep the link free of targeting rules.

## Reading the result

Analytics breaks clicks down by **destination**, which is where the variants show up side by side. Pick a range that covers the whole test period, and compare the destinations rather than the link total. See [Analytics](https://docs.zulink.co/design-and-analytics/analytics).

## Availability

A/B testing is part of the Scale plan.