Mobile Checkout Quality Benchmark: Top 100 Apps

Methodology

Each app's checkout flow was tested by a trained mobile tester using a standardised test script covering: product add-to-cart, checkout initiation, payment form entry (credit card, Apple Pay/Google Pay, BNPL), order confirmation, and error recovery. Tests ran on 20 real iOS devices (iPhone SE through iPhone 16 Pro Max) and 30 real Android devices (Pixel 3a through Pixel 9, Samsung Galaxy S series) across 4G, 3G, and low-bandwidth network conditions.

Key findings: checkout failure patterns

Across 100 apps and 5,000 test sessions, 12% of checkout attempts failed before order confirmation. The failure distribution was highly concentrated: the top 5 failure patterns accounted for 78% of all failures.

• Keyboard covering payment form fields (iOS): 24% of failures
• Decimal separator validation errors (Android, European payment methods): 18% of failures
• Session timeout during 3D Secure / SCA challenge: 16% of failures
• Apple Pay / Google Pay sheet dismissed without error message: 12% of failures
• Order confirmation page crash on slow network: 8% of failures

Device-specific patterns

Samsung Galaxy devices with One UI showed a significantly higher rate of keyboard-overlap issues (31% vs 18% on stock Android) due to One UI's full-screen keyboard mode defaulting to overlay rather than resize. iPhone SE users experienced disproportionate tap-target failures on payment CTAs, 44px height buttons failed at 3× the rate of 48px+ buttons on the SE's 4.7" screen.