10 A/B Tests Every E-Commerce Store Should Run (With Expected Lifts)
E-commerce conversion optimization has more data behind it than any other category of A/B testing. Millions of experiments have been run on product pages, cart flows, and checkout forms across every industry.
Here are the 10 highest-ROI tests to run first, ordered by expected impact.
1. Product Page — Above-the-Fold CTA
What to test: "Add to Cart" button — size, color, position, text
Control: Standard "Add to Cart" button, medium size, below product title
Variants:
- Larger button (40% more height), higher contrast color
- Sticky "Add to Cart" that follows the user as they scroll
- Text variation: "Add to Bag" / "Buy Now" / "Get Yours"
Expected lift: 5–25% in add-to-cart rate
Why it works: The CTA is the primary conversion action. Size and contrast directly affect click-through. "Add to Bag" outperforms "Add to Cart" on fashion sites in most tests; "Buy Now" outperforms for impulse purchases under $50.
2. Checkout — Number of Steps
What to test: Single-page checkout vs multi-step checkout
Control: 3-step checkout (cart → shipping → payment)
Variant: Single-page checkout with all fields visible
Expected lift: 15–35% in checkout completion
Why it works: Every additional page in checkout adds friction and dropout. Single-page checkout eliminates the "loading between steps" UX and shows the full scope of what's required — reducing surprise at the final step.
Caveat: This requires more engineering work than most tests. But the payoff (15–35% lift) makes it the highest-ROI test on this list.
3. Cart Page — Trust Signals
What to test: Security badges, guarantee text, and social proof near the checkout button
Variants:
- "🔒 Secure checkout" badge + SSL seal
- "30-day return guarantee" text
- "⭐⭐⭐⭐⭐ 4.9/5 from 8,400 customers" near checkout button
Expected lift: 5–15% in cart-to-checkout rate
Why it works: Cart abandonment often comes from anxiety, not decision fatigue. Trust signals at the last decision point address the most common hesitations.
4. Product Page — Image Gallery
What to test: Number of images, types of images, gallery layout
Variants:
- Lifestyle images (product in use) vs product-on-white
- Video demo as first gallery item
- Zoom functionality on hover
Expected lift: 10–20% in add-to-cart rate
Why it works: Online shoppers can't touch the product. Images are the primary trust-building mechanism. Lifestyle images (showing the product being used in context) consistently outperform studio shots on fashion and home goods.
5. Product Page — Social Proof
What to test: Reviews quantity, rating display, and review content selection
Variants:
- Show "4,283 reviews" vs just the star rating
- Pin the most helpful 1-star review at the top (counterintuitive, but increases trust)
- Show review count near the CTA button
Expected lift: 8–18% in add-to-cart rate
Why it works: The number of reviews is often more persuasive than the average rating. 500 reviews at 4.6 stars typically outperforms 20 reviews at 5.0 stars.
6. Cart Page — Upsell/Cross-sell Placement
What to test: "Frequently bought together" position and format
Variants:
- Inline in cart vs popup modal
- Before vs after the cart summary
- "Complete the look" (apparel) vs "Add accessories" (electronics)
Expected lift: 5–12% in average order value
Why it works: Cart page visitors have demonstrated intent to buy. Cross-sell to them at peak buying intent, not on the product page where purchase is uncertain.
7. Shipping Threshold — Display and Messaging
What to test: How prominently you show the free shipping threshold
Control: "Free shipping on orders over $75" in footer
Variants:
- Progress bar in cart: "Add $12 more for free shipping" with visual fill
- Persistent banner on product pages
- Threshold amount change ($50 vs $75 vs $100)
Expected lift: 8–20% in average order value
Why it works: Free shipping threshold messaging is the single most underoptimized conversion lever in e-commerce. Most stores mention it once in the footer. A prominent progress bar creates a goal-completion motivation that dramatically increases basket size.
8. Email Capture — Incentive Type
What to test: What you offer in exchange for email signup
Variants:
- 10% off first order
- Free shipping on first order
- Access to a sale (exclusive early access)
- No incentive, just "Stay updated"
Expected lift: 20–40% in email capture rate
Why it works: "10% off" is the default choice for 90% of stores. Because of this saturation, "free shipping" often outperforms it — it feels more tangible. "Early sale access" outperforms all on fashion/luxury.
9. Search → Product — Filter Experience
What to test: Search results page filtering UI
Variants:
- Faceted filters in sidebar vs chips at top
- "Most Popular" vs "Best Match" default sort
- Price range slider vs checkbox ranges
Expected lift: 10–25% in search-to-purchase rate
Why it works: Poor filter UX is the top reason search users don't find what they're looking for. If 30% of your traffic enters through site search, filter UX improvements have an outsized impact.
10. Post-Purchase — Re-engagement
What to test: What you show on the order confirmation page
Control: Basic order summary
Variants:
- Product recommendation widget (complementary items)
- Referral offer ("Give a friend 15% off, get 15% off your next order")
- Account creation CTA with benefit framing ("Save your details for faster checkout next time")
Expected lift: 5–15% increase in second purchase rate (measured 30 days later)
Why it works: Immediately post-purchase is peak brand affinity. Customers are happy and engaged. Most stores show a receipt — a missed opportunity to drive the next action.
Setting Up Revenue Tracking for E-Commerce Tests
To measure impact on actual revenue (not just CVR), add revenue tracking to your checkout:
// On order confirmation page
window.ghostsnip.track('purchase', {
revenue: 89.99,
currency: 'USD',
orderId: 'ord_123'
})
GhostSnip will automatically show revenue per visitor for each variant in your results — so you can see if a CVR lift comes with a basket size trade-off.