iPhone Duo vs Xiaomi 18 Fold

Build and design

The Duo is 254g, 5.2mm unfolded and 11.3mm folded, with a hinge, an inner display and an outer display for quick use. The Xiaomi is lighter at 219g, 5.0mm unfolded and 10.7mm folded, with a passport-sized folded form that Xiaomi calls a mid-fold, between book-style and flip phones. Both phones are thin unfolded, but the Xiaomi wins on weight and folded thickness on paper.

Water rating is a flagged disagreement for the Xiaomi: one listing gives IP58/IP59, while another report says Xiaomi gave no water or dust rating at IFA. Do not buy either foldable on a water rating alone — check Xiaomi's official listing for your exact model, and treat the Duo's durability as a long-term review question, as with any foldable.

Display and benchmarks

The Duo offers a 7.6-inch inner display at 1878 x 2670 and a 5.4-inch outer display at 1398 x 2034, both ProMotion and Always-On, with up to 3,000 nits in one listing. The Xiaomi offers a 7.58-inch inner display at 2364 x 1672 with 1–120Hz and a 5.38-inch cover display at 1712 x 1168, with up to 4,000 nits peak in one listing. Both inner displays are almost identical in size, so the difference is not size, but brightness and software — the Xiaomi's cover is passport-sized for one-handed use, while the Duo's outer is slightly larger.

On benchmarks, the Duo uses A20 Pro and the Xiaomi uses its own XRing O3 chip on 3nm, with ten cores up to 4.35GHz and a 16-core GPU, with Xiaomi claiming an 85% GPU improvement over its predecessor — a self-reported claim, not an independent benchmark. No controlled side-by-side benchmark between these two phones was reviewed, so no speed winner is claimed. For multitasking, both should handle three apps side by side on their inner displays, with the Xiaomi's up to 16GB RAM helping on paper.

Cameras and video

The Duo offers dual 48MP cameras, a Fusion main and a Fusion ultrawide, with no telephoto, plus a 12MP Centre Stage front camera. The Xiaomi offers a 200MP main with OIS, a 50MP telephoto at 3.5x with OIS and a 50MP ultrawide, with Leica lenses and laser autofocus. On paper, the Xiaomi wins on megapixels, telephoto and main-camera resolution, while the Duo wins on simplicity and Apple video pipeline.

No controlled side-by-side camera test between these two phones was reviewed, so no photo winner is claimed beyond the hardware gap. If you shoot zoom often, the Xiaomi is stronger on paper. If you shoot video and want Apple's ProRes pipeline, the Duo is stronger on paper. For everyday photos at 1x, both should be close, despite the megapixel gap.

Battery, software and price

Battery is where the Xiaomi wins on paper, with 6,000mAh and 67W wired and 50W wireless charging, versus a reported 5,400mAh dual-battery system for the Duo in one comparison table — a figure that is not an Apple disclosure, so treat it as reported, not official. For most users, the Xiaomi will last longer on paper, while the Duo's battery will vary with inner versus outer use. Charging is faster on the Xiaomi on paper, though real-world charging should be checked in reviews.

Software is iOS 27 on the Duo, with foldable multitasking and, in reports, a side Touch ID button, while the Xiaomi runs HyperOS 4 on Android 17 in China, with no confirmation of which Google services its Chinese firmware includes — a practical obstacle for import buyers. In the US and Europe, the Duo is the only one you can buy today, from $1,999 in the US and €2,299 in Germany.

Verdict

Buy the iPhone Duo if you want a foldable in the US from $1,999 or in Europe from €2,299 in Germany. Do not buy the Xiaomi 18 Fold in the US or Europe on specs alone, because it is China-only for now, with no confirmed launch. For most US and Europe buyers, the Duo is the only choice — the Xiaomi is a wait-and-see import.