Mobile checkout is the part of the purchase flow a shopper completes on a phone: cart, contact and shipping details, payment and order review.
The changes that win most often in real A/B tests are a short, mobile-first cart, express wallets placed where they don't skip the cart, fewer and better-labeled fields, and a pay button that stays in thumb reach.
Test each one on mobile traffic alone, because the same change can win on desktop and lose on phones.
This page covers the checkout itself. For product pages, menus and galleries, see our guide to mobile conversion rate optimization.
For the full device-agnostic list, use the checkout checklist.
Mobile checkout optimization: what the tests show
Checkout is where small screens hurt most. Baymard Institute's benchmark finds the average US checkout shows 23.48 form elements by default (14.88 counting only fields), while its testing suggests 12-14 elements is enough.
On a phone, each of those fields means a tap, a keyboard and a scroll.
Baymard puts the average documented cart abandonment rate at 70.22%, based on 50 studies.
That figure covers all devices. For how your own numbers compare, see our cart abandonment benchmarks and mobile vs desktop conversion rates.
Fixing a broken mobile flow beats any single tweak
The biggest result in our database here is a repair, not an optimization.
Clean Commit rebuilt an anonymized Shopify store's mobile cart and checkout with faster pages, better touch interactions, fewer fields and a simpler payment flow.
Orders rose 100% even though visitors fell 12.2%.
Clean Commit notes the control had near-zero mobile conversions, so this was a broken flow being fixed.
Before you test anything subtle, buy something on your own store from two or three real phones.
If a step fails, fix it and skip the test.
Mobile-first carts lift checkout visits
Surefoot redesigned SMITH's mobile cart: bigger buttons and tap targets, a simpler layout, easier cart editing and one primary call to action at the bottom.
Visits to checkout on mobile rose 8% at 95% significance, and 10% among returning mobile visitors.
A VWO case study on Hush Blankets removed the header and footer navigation from the mobile cart, removed poor reviews and made the cart update automatically when quantity changed.
Over 14 days the variant showed +10.52% checkout visits, +15.48% purchases and +23% revenue.
Three changes were bundled, so you can't credit any one of them.
Not every declutter clears the bar. Clean Commit's mobile-first mini cart showed +7.5% conversion rate across 35,480 visitors, but with an 86.2% probability to beat control.
That's a positive signal, not a proven win.
Express wallets: in the cart, carefully on the product page
Wallets like Apple Pay, Shop Pay, Google Pay and PayPal skip most typing, which matters more on a phone than anywhere else.
Blend Commerce tested express checkout buttons in the cart for a sports nutrition brand: +26.2% revenue per visitor overall and +53.29% RPV on mobile.
A dedicated Shop Pay button in Fame's cart drawer lifted conversion rate 47.75%.
On the product page the evidence flips. For a travel gear brand, a dynamic express checkout button under Add to Cart cut mobile conversion rate 14% and mobile RPV 21%.
Removing express buttons from Jackson's product pages raised RPV 66.18% at 93.82% significance.
A likely reason: a wallet button on the product page lets shoppers buy one item and skip the cart, along with its upsells and free-shipping bar.
When Stone Creek Coffee removed product-page express buttons, conversion rose 13% (86% significance), but subscription orders per visitor fell 7.21%.
Check the metrics you care about, not just the headline one.
More on placement in payment icons and express checkout.
Clean Commit
Surefoot
Blend CommerceSurefootBlend CommerceMobile checkout best practices
These are the practices with test evidence or a clear technical basis behind them.
Treat each as a hypothesis for your store, not a guaranteed lift.
| Practice | Evidence | Watch out for |
|---|---|---|
| Sticky pay button showing the order total | Utsav Fashion: +9.98% purchases, +8.95% revenue (bundled) | Covering form fields or error messages |
| Express wallets in the cart | Sports nutrition brand: +53.29% mobile RPV | Product-page wallets lost on mobile for a travel brand |
| Fewer, clearer fields | BioLite: +18% transactions; KoRo: +0.9% RPU | Dropping data you need for delivery or email |
| Strip navigation and extras from the cart | Hush Blankets: +23% revenue (bundled) | Hiding the way back to shopping |
| Correct keyboards and autofill | Technical standard (MDN); few public A/B tests | Autocomplete set to "off" by a theme or app |
Keep the pay button and total in thumb reach
On a long mobile checkout, the main button often sits below the fold.
Utsav Fashion's VWO test added a sticky bottom button showing the order total, collapsed the order summary behind a "View Details" link and removed an Edit link.
Over 16 days on US mobile traffic, purchases rose 9.98% and revenue 8.95%. Three changes were bundled.
Size tap targets for thumbs. WCAG 2.2's AA criterion asks for targets of at least 24 by 24 CSS pixels, and Apple's guidelines recommend 44x44 points on iOS.
Treat 24 as the floor and 44 as the target for the pay button, quantity steppers and remove links.
The sticky add-to-cart pattern on product pages works on the same idea.
Ask for less, and explain what you ask for
Every field costs more on a phone. DRIP Agency removed optional fields such as birthdate from KoRo's checkout, and revenue per user went from €68.83 to €69.44 (+0.9%).
Small, but positive. In a VWO case study, GANNI merged its email step into the information step, and the page's summary lists a 10% checkout lift.
Explaining fields can work as well as cutting them.
Surefoot moved email and phone into a labeled contact block with helper text on BioLite's Shopify checkout. Transactions rose 18% and email capture 20%.
Coupon boxes are a known distraction. Sq1 removed the coupon and gift card fields from Bionic Gloves' cart and revenue rose 24.7%, though the test had only about 1,400 visitors and no stated significance.
See form fields and guest checkout for more.
Trigger the right keyboard and let autofill work
This is the most mobile-specific fix and usually the cheapest.
Use type="email" and type="tel" for those fields, and inputmode="numeric" for card numbers and numeric ZIP codes, which MDN describes as showing a digits-only keyboard.
MDN notes inputmode is only a hint and doesn't validate input.
Add autocomplete tokens such as name, email, tel, street-address, postal-code, cc-number, cc-exp and cc-csc, so the phone can fill fields from saved details.
Many sites still get this wrong: Baymard's 2015 benchmark found 54% of 48 leading mobile sites failed to show optimized keyboards for phone, ZIP or card fields.
That data is old, so audit your own checkout rather than assume.
Hosted checkouts such as Shopify's handle most of this for you.
Custom checkouts, apps and embedded forms are where it breaks. Speed matters here too; see page speed.
Where to start
- Place real orders from two or three phones, including an older Android device, and note every step that fails, stalls or hides the button.
- Fix keyboard types and autocomplete attributes. These are technical corrections, so ship them without waiting for a test.
- Test a simpler mobile cart: one primary button, no header or footer navigation, a visible subtotal.
- Test express wallets in the cart or cart drawer before trying them on the product page.
- Test a sticky pay button with the order total, then trim or explain fields one group at a time.
Run one change at a time when you can.
The bundled tests above show what a full redesign can do, but they can't tell you which part did the work.
Test on mobile traffic, and read results by device
Run checkout tests on mobile visitors only, or at least report mobile and desktop separately.
The travel brand's product-page test was negative overall, yet payment icons were +1% conversion and +2% RPV on mobile.
Blend Commerce rolled them out on mobile only, as a directional call.
Use revenue per visitor or completed orders as the main metric, not clicks to checkout.
A cart change can raise checkout visits while orders stay flat.
Then check secondary metrics like subscriptions or AOV, as the Stone Creek test shows.
Browse more checkout and cart results in the test database, or start from the wider checkout flow guide and our CRO hub.