Sticky mobile filter button on collection pages: -16.0% conversion
Test run byClean CommitCRO agency
Commentary byLiftArchiveOur analysis, not theirsFixing the filter button to the bottom of the screen on mobile collection pages cut conversion rate 16.0%.
Clean Commit ran this test for an anonymized Shopify store and published it in its A/B test library.
The original had a 95.7% probability of performing better, though the test lasted only five days.
- Conversion rate: -16.0%, with a 95.7% probability that the original performs better.
- Orders: -16.4%, a clear drop in buyers.
- Revenue per visitor: -5.0%. Average order value rose 11.6%, which softened the loss.
- Add-to-cart rate: -4.2%, so fewer shoppers got as far as the cart.
The change
The variant pins the filter button to the bottom of the mobile screen.
Simplified mockup drawn by LiftArchive from the shared screenshots.
Control
The mobile filter button sat in its normal place on the collection page and scrolled away with the content.
Variant
The filter button stayed fixed to the bottom of the screen as shoppers scrolled. Tapping it opened the same filter panel as before.
Why it likely lost
Our reading of the result, not the practitioner's claim.
- A button pinned to the bottom of a small screen covers part of the product grid and may feel in the way.
- Bottom-of-screen space on mobile is often used for chat widgets or cookie bars, so the button may have clashed with them.
- A constant prompt to filter may pull shoppers into narrowing options instead of picking a product.
Caveats: The test ran just 5 days on 14,858 mobile visitors, which is short and may miss weekly patterns. Order value rose 11.6%, so the revenue cost was smaller than the conversion drop.
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 keep the mobile filter button fixed on screen, then more shoppers will filter and find products because the button is always in reach.
- Primary metric
- Mobile conversion rate
- Guardrails
- Add-to-cart rate
- Revenue per visitor
- Filter usage rate
- Who should test it
- Stores with large mobile catalogs where filter use is low. Run it for at least two full weeks; if your product grid is already short, a sticky button is unlikely to help.
Questions
Should the filter button be sticky on mobile?
In this test it cost 16% of conversions.
A fixed button can cover products and distract, so test it before rolling it out.
How long should a collection page test run?
Usually at least one or two full weeks, to cover weekday and weekend behavior.
This test ran 5 days, which is on the short side.
Why would a usability fix hurt sales?
A change can look helpful and still add clutter or pull attention away from products. Testing shows the real effect.
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