No flicker

The group is decided before the page paints

Shoppers never see the control and then the change. On a Shopify theme the test set-up is already in the page, so the decision needs no network request.

Book a call Developer docs

Page load, frame by frame

Frame 1 is blank: nothing has painted yet
From frame 2, every frame shows group B
No frame shows the control first

How it stays still

Fast for shoppers, honest for results

In the page

The app embed renders just before the closing head tag with the set-up inlined, under 6 KB gzipped.

TraditionallyA script that loads late

With Growth Dept CROA decision before paint

Control hidden, then shown

Default styles show only the control until the runtime marks the page ready.

TraditionallyA flash of the old page

With Growth Dept CROOne version from frame one

Redirects in the same tick

A split URL redirect hides the page in the same tick and keeps the whole query string.

TraditionallyA visible bounce

With Growth Dept CROA clean hand-off

Tested per frame

Checked frame by frame

Browser tests read which group is visible on every animation frame, in Chromium and WebKit, and fail if any frame shows the wrong one.

Headless

Decided on the server

Next.js middleware and a Cloudflare Worker decide the group on the server and rewrite split URL groups under the original address.

Find out what is worth testing on your store.

Book a 45-minute call with the Growth Dept team. We look at your store and your traffic, and tell you which tests to run first.

Book a call