A/B test: a free shipping progress bar in the cart
If the cart says "You're €12 away from free shipping" with a progress bar, then average order value will rise, because the goal is visible, it is close, and the shopper doesn't have to do the maths.
By Fernando Blanco Dosil · Updated November 2, 2026
Why it might work
You have €37 in your cart and shipping costs €4.95. If you knew that €12 more gets you free shipping, adding a €9 pair of socks would feel almost free. But to think that you need to know the threshold, remember it and subtract. Hardly anyone does.
The bar does the maths and turns it into something you can complete. Same logic as the threshold in the top bar, but at the moment the shopper is looking at their total.
How to set it up
In Bixlow you describe the change to the agent, it builds it on your site and launches it as an A/B test once you approve it.
- In the variant, add a line at the top of the cart (and the mini cart if you have one) with the amount left and a bar that fills up.
- Once the threshold is passed, change the text to something like "You've got free shipping".
- Make the text state the amount; a bar on its own means nothing to a screen reader.
- Run it for all traffic that reaches the cart.
What to measure
| Metric | |
|---|---|
| Primary metric | Average order value |
| Metric that must not get worse | Orders per visitor |
| Where it is measured | Visitors who reached the cart |
Other variants worth trying
Under the bar, suggest two or three low-priced products that close the gap. It is a different test, because it adds an action as well as a message, and it gets its own page.