Galaxy S27 Ultra vs Xiaomi 18 Pro Max: Future Battle

Build and design

The Xiaomi is a larger flagship at 6.9 inches, with a 2.9-inch rear display for selfies and notifications, plus a dual-200MP Leica camera island. The S27 Ultra is leaked to keep a similar 6.9-inch front design, with a raised camera island, or Camera Plateau, replacing the floating camera rings, and slimmer bezels at 1.21–1.28mm. Colours tipped are Black, Blue, Light Pink and White, plus a special Violet option.

If you want a proven camera phone today, the Xiaomi wins. If you want a new camera island and slimmer bezels, the S27 Ultra is a wait-and-see leak. For most buyers, the Xiaomi is the safer choice in China until Samsung announces the S27 Ultra.

Display and benchmarks

The Xiaomi offers a 6.9-inch LTPO AMOLED at 120Hz, plus a 2.9-inch rear display. The S27 Ultra is leaked to offer a 6.9-inch display at 1440 x 3120, with a next-generation M16 OLED panel and a second-generation Privacy Display, which should help brightness and power efficiency. For everyday use, both displays are flagship-grade on paper, with the S27 Ultra winning on panel generation only if the leak is confirmed, and the Xiaomi winning on rear-display features.

On benchmarks, the Xiaomi uses Snapdragon 8 Elite Extreme Gen 6 and the S27 Ultra is leaked to use Snapdragon 8 Elite Gen 6 Pro for Galaxy, also on 2nm, so no chip winner is claimed — a controlled side-by-side benchmark between these two phones does not exist, and the Pro variant is a leaked Samsung customisation, not a confirmed chip. For sustained performance, the S27 Ultra's cooling is not confirmed, while the Xiaomi's chip is proven in reviews.

Cameras and video

The Xiaomi offers dual 200MP Leica cameras — a main at 1/1.28-inch and a periscope at 1/1.56-inch, 75mm, 3.2x with 12cm macro — plus a 50MP ultrawide and a 50MP front camera. The S27 Ultra is leaked to offer a triple camera: 200MP ISOCELL HP6 main, a 50MP ultrawide and a 50MP 5x telephoto, plus a 16MP selfie camera. On paper, the Xiaomi wins on dual 200MP and macro, while the Samsung wins on 5x telephoto.

No controlled side-by-side camera test between these two phones exists, so no photo winner is claimed beyond the leaked hardware gap. If you shoot zoom often, the Samsung's 5x telephoto is stronger on paper. If you shoot macro often, the Xiaomi's 12cm macro is stronger on paper. For selfies, the Xiaomi's rear display and 50MP front camera are stronger on paper.

Battery, software and price

Battery is where the Xiaomi wins on paper in China, with 8,500mAh and 100W wired and 50W wireless charging, versus the S27 Ultra's leaked rated 5,534mAh, typically around 5,700mAh, with 60W wired and 25W wireless charging leaked. In Europe, the Xiaomi's battery is reported at 7,050mAh, which would still make the Xiaomi larger on paper if that figure is confirmed. For most users, the Xiaomi will last longer on paper, while the Samsung's battery is leaked only. Charging is faster on the Xiaomi on paper, though real-world charging should be checked in reviews.

Software is leaked as One UI 9.5 on Android 17 with 7 years of OS upgrades for the S27 Ultra, while the Xiaomi runs HyperOS 4. In China, the Xiaomi starts at CNY 6,999 for 12GB/256GB, while the S27 Ultra has no announced price — a price hike is tipped, but no figure is confirmed. In the US and Europe, neither is officially sold, so do not treat a China price or a conversion as a US or Europe price.

Verdict

Buy the Xiaomi 18 Pro Max if you want a dual-200MP Leica flagship with a rear display, in China from CNY 6,999. Wait for the Galaxy S27 Ultra if you want its leaked 5,700mAh battery, M16 display and triple-camera setup, and check Samsung's announcement in early 2027. For most US and Europe buyers, neither is officially sold today — both are wait-and-see, with the Xiaomi's global launch later in 2026.