Most CRO articles list "10 quick wins" with no data. This isn't that. These are 15 patterns that won across at least three different UK Shopify stores, reaching statistical significance at p<0.05, with effect sizes large enough to matter.
How we measure.
For each test below, we required:
- Minimum sample size calculated upfront for the expected effect size at 80% power.
- p<0.05 on the primary metric (CR or revenue per visitor).
- Replicated on at least three different Shopify stores in different verticals.
- No "winner" called early — tests run their full duration regardless of interim results.
PDP wins (5).
- Sticky add-to-cart on mobile. +12–18% mobile CR. Ship as a position-fixed bar that activates after scrolling past the primary ATC.
- Variant images in main gallery. +6–11% PDP CR. When the customer selects a colour, the gallery should change. Most Shopify themes don't do this by default.
- Inline review average + count above the ATC. +4–7% CR. "★★★★☆ 4.6 (1,247 reviews)" — visible in the first viewport.
- Stock urgency where genuine. +5–9% CR. "Only 4 left" — but only when true. Faking it loses more than it gains in repeat visits.
- Specifications in a structured table, not bullets. +3–5% CR for considered purchases. Bullets get skipped; tables get scanned.
Cart wins (3).
- Free shipping threshold progress bar. +8–14% AOV. "Spend £X more for free shipping" with a visual bar. Live-updates as items are added.
- Drawer cart over page cart. +6–10% conversion. Drawer keeps customers on the PDP context. Full-page cart breaks the browse flow.
- Recommended add-ons in cart, not on PDP. +4–7% AOV. Discovery on PDP, accept-decline in cart. Customers in cart are committed.
Checkout wins (3).
- Express checkout above email field. +9–15% checkout CR. Apple Pay, Shop Pay, PayPal — surfaced before the customer types anything.
- Address autocomplete on shipping. +4–8% checkout CR, especially mobile. Loqate or Google Places. Reduces typing-by-thumb.
- Order summary always visible (sticky on mobile). +3–6% checkout CR. Confidence wobbles when the cart contents disappear during shipping/payment steps.
+12%
AVG WIN SIZE
when significant
38%
WIN RATE
incl. neutrals
Mobile-specific wins (4).
- Hamburger nav with featured collections. +5–9% mobile CR. Customers don't browse mobile mega-menus; they tap categories and judge by the first 3 products.
- Filters as bottom-sheet, not sidebar. +7–12% mobile PLP CR. Sidebar filters on mobile are a desktop pattern that lost.
- Tap targets ≥48px. +3–6% mobile CR across the funnel. The Web Content Accessibility Guidelines minimum is also the conversion minimum.
- Image-first PDP gallery (swipe, not tap). +6–11% mobile CR. Gallery should be the first thing under the title; gallery should swipe, not tap-to-zoom.
Things that didn't work.
Equally important. These tested as flat or worse across multiple brands:
- Exit-intent popups — flat in 7/8 tests. Annoying, no significant CR uplift.
- Countdown timers on PDP — flat to negative. Customers see through fake urgency.
- "X people viewing now" widgets — flat to negative. Same trust erosion.
- Quiz funnels for non-quiz products — negative. Quizzes work for skincare and supplements; they kill conversion on basics.
- Live chat widgets — flat to slightly negative on CR. Useful for support, not for conversion.
The pattern: anything that feels manipulative wins short-term, then loses trust on repeat visits. The 15 wins above all add information or remove friction. That's the through-line.
