Low-stock announcement bar on product pages: -17.5% conversion rate
Test run byClean CommitCRO agency
Commentary byLiftArchiveOur analysis, not theirsAdding an announcement bar that warned stock was running low cut conversion rate by 17.5% and orders by 18.5%.
Clean Commit ran this test for an anonymized Shopify store and published it in its A/B test library.
The original had a 93.8% probability of doing better after 6 days.
- Conversion rate: -17.5%, a clear negative result. The original had a 93.8% probability of being better.
- Orders: -18.5%.
- Revenue per visitor: -11.3%, a smaller drop because average order value rose 7.4%.
- Conversion rate fell on both mobile and desktop.
The change
A low-stock warning bar is added above the product page header.
Simplified mockup drawn by LiftArchive from the shared screenshots.
Control
Product pages showed no message about stock levels.
Variant
A prominent announcement bar on product pages told shoppers stock was low. It was designed to stand out on mobile.
Why it likely lost
Our reading of the result, not the practitioner's claim.
- A generic stock warning can read as a sales trick and lower trust.
- Shoppers may worry their size or color is gone and leave instead of checking.
- A loud bar at the top pulls attention from the product and the buy button.
Caveats: Small, short test: 5,161 visitors over 6 days. The direction held on both devices, but the size of the drop is uncertain.
Who ran it
Clean Commit ran this test for a Shopify store (anonymized) and published the results (Clean Commit A/B test library). The numbers are theirs; the summary and commentary on this page are ours.
Read the original case study on Clean Commit →
How to run this test on your store
- Hypothesis
- If we show a low-stock announcement bar on product pages, then conversion rate will rise because shoppers feel urgency to buy before items sell out.
- Primary metric
- Conversion rate
- Guardrails
- Orders
- Revenue per visitor
- Bounce rate
- Who should test it
- Stores with real, product-level stock limits, such as small-batch drops. If stock is not actually low, or the message is the same on every product, expect it to hurt trust.
Questions
Do low-stock messages increase sales?
Not always. In this test, a general low-stock bar on product pages cut conversion rate by 17.5%.
How should I show scarcity without hurting trust?
Tie it to real stock on the specific product or variant, and keep it small.
A blanket warning is easy for shoppers to doubt.
Similar tests
@oliverkenyon@oliverkenyon
@DaveDiederen@DaveDiederen@DaveDiederen