Thumbnail strip on mobile product gallery: +1.71% conversion rate
Test run byBlend CommerceCRO agency
Commentary byLiftArchiveOur analysis, not theirsAdding a row of image thumbnails to the mobile product gallery lifted conversion rate by 1.71%.
Blend Commerce ran this two-week A/B test for a supplements brand.
Add-to-cart and checkout visits also rose, and the thumbnails were kept.
- Conversion rate: +1.71%. A small but real gain for a low-effort design change.
- Add to cart: +2.5%. More shoppers moved from browsing to adding the product.
- Checkout visits: +3.44%. The lift carried through the funnel rather than stopping at the cart.
- Confidence level and sample size were not shared.
The change
The variant adds a thumbnail strip under the main product image on mobile.
Simplified mockup drawn by LiftArchive from the shared screenshots.
Control
The mobile product page showed one main image with no visible thumbnails. Session recordings suggested many shoppers did not realise there were more photos to see.
Variant
A strip of thumbnail images was added to the product gallery, so shoppers could see at a glance how many photos there were and tap straight to one.
Why it likely won
Our reading of the result, not the practitioner's claim.
- Thumbnails signal that more images exist. Without them, many mobile shoppers assume the first photo is all there is.
- Seeing the product from more angles, plus packaging and label shots, answers questions that would otherwise stall a purchase.
- Tapping a thumbnail is quicker than swiping blind through a carousel, so more images actually get viewed.
Caveats: The test ran for two weeks. Sample size and statistical confidence were not shared, and the lift is small enough that it could sit within normal noise.
Who ran it
Blend Commerce ran this test for a supplements brand and published the results (Blend Commerce A/B test). The numbers are theirs; the summary and commentary on this page are ours.
Read the original case study on Blend Commerce →
How to run this test on your store
- Hypothesis
- If we add visible thumbnails to the mobile product gallery, then more shoppers will add to cart because they will find and view the extra product images.
- Primary metric
- Conversion rate on product pages (mobile)
- Guardrails
- Page load time on mobile
- Add-to-cart rate
- Image gallery interaction rate
- Who should test it
- Stores whose mobile gallery hides extra images behind swipe gestures or small dots, especially where products need close inspection. Less likely to help if you only have one or two images per product.
Questions
Do product image thumbnails increase conversions?
In this test, adding thumbnails on mobile raised conversion rate by 1.71% and add to cart by 2.5%.
The effect is usually modest, but the change is cheap to make.
Are thumbnails better than dots on a mobile product carousel?
Thumbnails show what each image contains, while dots only show how many there are.
That makes it easier for shoppers to jump to the photo they care about.
How many product images should a product page have?
Enough to answer the main questions a shopper has, such as size, texture, label and use.
The gallery only helps if shoppers can tell those images are there.
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