Samsung Galaxy S21+ vs Xiaomi 15 Ultra

The Verdict

Comparing flagships from 2021 and 2024 reveals substantial generational improvements favoring the Xiaomi 15 Ultra. Samsung's S21+ features a respectable 6.7-inch Dynamic AMOLED display with 120Hz refresh and 1300 nits brightness, paired with Snapdragon 888 performance and a versatile triple camera setup including 64MP telephoto with 3x zoom. The 4800 mAh battery supports 25W charging. Xiaomi's 15 Ultra counters with a larger 6.73-inch LTPO AMOLED display pushing 3200x1440 resolution and 3200 nits peak brightness, alongside the significantly more powerful Snapdragon 8 Elite. Its camera system is exceptional: a 50MP main shooter with 1-inch sensor, 50MP ultrawide, and standout 200MP telephoto with 5x periscope zoom and OIS. Battery capacity jumps to 5810 mAh with rapid 90W wired and 50W wireless charging. Both cost $999, but Xiaomi delivers superior specs across nearly every metric: 16GB RAM versus 8GB, 256GB base storage versus 128GB, and Wi-Fi 7 against Wi-Fi 6. The S21+ remains a capable performer for 2021, but the Xiaomi 15 Ultra represents current-generation flagship technology with meaningfully better photography, charging speeds, display clarity, and processing power. For the identical price, Xiaomi offers substantially more capability.