---
title: "A/B tests | Briks"
url: https://briks.dev/docs/ab-tests
description: "Test a saved version of your site against the live one: start it from Versions, see which converts more visitors, then keep the winner. With a worked example."
last_updated: 2026-10-08
---

# A/B tests

An A/B test shows two versions of your site to different visitors at the same time and counts which one gets more of them to call, email, send a form or click your main button. You pick a saved version, Briks runs it beside the live one, and when the numbers are clear you keep the winner.

6 minute read Checked against the studio on 8 October 2026

## Before you start

- **Two versions.** One side of a test is always the version that's live when you start. The other is any saved version you pick. So make the change you want to test first, then decide which version should be live.
- **Real visitors.** Each version needs about 100 visitors before the result means much. A preview address is kept out of search engines and rarely gets that many, so most tests belong on a site in production.
- **Edit rights.** Editors, Admins and Owners can start and end tests.
- **A quiet moment.** A test can't start while something is building, and a site runs one test at a time.

## Start a test

1. Make the version you want to test

   Where: Studio

   Ask for the change, such as a new hero headline. It becomes the newest version and goes live.

2. Decide which goes live

   Where: Preview toolbar

   If you'd rather the old version stays live while you test, press undo. Either way works: one side is live, the other is the one you pick.

3. Pick the other version

   Where: Versions

   Open **Versions**, find the version that isn't live and press **Test against live**.

4. Wait for it to publish

   Where: Studio

   Briks publishes both versions together and replies “The A/B test is live: new visitors are split between the two versions, and each visitor keeps the one they first saw.”

5. Find the results strip

   Where: Preview

   A strip headed **A/B test** appears above the preview, marked **Running**.

Where

1. Projects
2. Your project
3. Studio
4. Versions
5. Test against live

## How visitors are split

When you press **Test against live**, choose how many new visitors see the version under test: **Half (50%)**, **A quarter (25%)**, **A tenth (10%)**, or **Custom** for any share from 5 to 95 percent. Then press **Start test**. The strip says how the split stands, for example “90% see v11, 10% see v12”. A smaller share is gentler on a bold change, but takes longer to give a clear answer.

Each visitor keeps the version they first saw, through a cookie that lasts 30 days. Every page they open comes from their version, so someone who reads the home page, leaves and comes back next week still sees the same one.

Tests use a cookie

Briks's analytics count visits without cookies, but a test needs one to keep each visitor on the same version. If your site's privacy notice lists the cookies it uses, mention this one while a test runs.

## What counts as a conversion

| What a visitor does | Counts as |
| --- | --- |
| Taps a phone number link | A conversion |
| Taps an email address link | A conversion |
| Sends any form on the site | A conversion |
| Clicks the site's main action, such as **Book a visit** | A conversion |
| Opens the site | A visitor |
| Does two of these, or one twice | One conversion |

Each visitor counts once as a visitor and at most once as a conversion. Counts from one internet address are also capped at 20 an hour, so nobody can tilt a test by reloading.

Keep the main button pointing the same way

The main action is read from the version that was live when the test started: it's that button's link. If the other version sends its main button somewhere new, clicks on it won't count, though calls, emails and forms still will. Test words, pictures and layout, and keep the button's destination the same.

## Read the results

The strip refreshes every 15 seconds while the studio is open. Each version has its own box: the share of its visitors who converted, then a line such as “18 of 410 visitors converted”. The version that was live when you started is marked “live before the test”. Under the boxes, one line sums it up:

| The line says | What it means |
| --- | --- |
| “Collecting visitors. Each version needs about 100 before the result means much.” | At least one version has fewer than 100 visitors. Keep waiting. |
| “No clear winner yet.” | There's enough traffic, but the difference could still be chance. |
| “Version 12 is very likely better.” | There's at least a 95 percent chance that version converts better. |

The same line gives the **Change in conversion** (how much better or worse the version you picked does, in percent) and the **Chance** that it converts better.

Give it time

Decide how long to run before you start, and include whole weeks: many businesses get different visitors on a Monday than on a Saturday. An early lead often shrinks.

## End the test and keep the winner

1. Choose the version

   Where: A/B test strip

   Press **Keep v11** or **Keep v12**.

2. Wait for the publish

   Where: Studio

   Briks publishes the kept version for everyone and replies, for example, “The test has ended. Version 12 is live for everyone.”

3. Carry on

   Where: Studio

   The kept version is the live one now. Your next change starts from it, and undo and redo work again.

Keeping a version is the only way to end a test. Starting and ending one hold no credits, because both publish saved versions without building.

## What's locked while a test runs

Both versions are published together, so anything that would publish something new waits until you keep one. While a test runs you can't:

- ask for a change (“An A/B test is running on this site. End it by keeping one version, then ask for your change.”);
- undo, redo or press **Make live**;
- start another test;
- save code from the File Explorer, publish from the Visual Editor, or **Replace** a picture on the **Media** tab;
- use **Apply to the live site**, **Publish** or **Back to preview**;
- save the project as a template, or change its address.

Questions still work: you can ask Briks about the site at any time. See [Asking questions](https://briks.dev/docs/asking-questions).

## Worked example: a plumber tests two headlines

Harbour Plumbing is a sample business: a two-person firm in Bristol whose site is in production. Its hero headline reads “Plumbing and heating repairs across Bristol”. The owner suspects a promise about speed would bring more calls.

The change v12

> `Change the hero headline to: A plumber at your door within two hours. Keep everything else the same.`

v12 went live with the new headline.

Setting up Undo, then test

> The owner pressed undo so the original headline (v11) was live again, opened **Versions**, and pressed **Test against live** on v12.

Half of new visitors saw v11 and half saw v12. Taps on the header's phone link, sent contact forms and clicks on **Book a visit** all counted.

Three weeks later The strip

> v11, live before the test: 4.4%, 18 of 410 visitors converted. v12: 7.8%, 31 of 398 visitors converted.

“Version 12 is very likely better. Change in conversion: +77.4%. Chance v12 converts better: 98%.”

Keeping the winner Keep v12

> The owner pressed **Keep v12**.

“The test has ended. Version 12 is live for everyone.” Their next change, adding Sunday call-out prices, was made from v12.

### Can I test two versions when neither is live?

No. One side is always the version that's live when the test starts. Make the other one live first with **Make live** if you need to.

### Can I change the split?

Yes, when you start the test: half, a quarter, a tenth, or any share from 5 to 95 percent. A running test keeps its split; to use another, end it and start a new one.

### Who sees the results?

Everyone in the workspace who opens the project's **Studio** tab, Viewers included. Only Editors, Admins and Owners can end the test.

## Read next

- [Working on a project **Versions, undo and redo** Every build and change is saved as a version of your site. Undo a change, redo it, or put any earlier version back live exactly as it was, with no credits held.](https://briks.dev/docs/versions)
- [Your site's features **Analytics** See who visits your site, where they come from and what they do, counted without cookies. Ask about your visits in plain words, set goals and get weekly emails.](https://briks.dev/docs/analytics)
- [Your site's features **Forms** Add a form to your Briks site, test it in preview, find every entry in the studio, get each one by email in production and pass them on with a webhook.](https://briks.dev/docs/forms)
- [Publishing and domains **Publish to production** Take a Briks site from preview to production: what the launch check reads, what blocks a launch, how to fix each finding and how to go back to preview.](https://briks.dev/docs/publish-to-production)

Still stuck?

Write to [hello@briks.dev](mailto:hello@briks.dev) with your project's name and what you expected to see. A screenshot helps.