But despite its elegance, the Mix Fold 4 lacks neither performance nor components.
Hardware and design
The Mix Fold 4 is an 8-inch tablet by default that folds in half like a book. When closed, it uses a secondary 6.5-inch screen on the outside.
The phone’s traditional screen format, slim design and light weight (228 g) give it the feel and functionality of a regular phone.
This slimming down is impressive considering that the Mix Fold 4 doesn’t skimp on components.
It has a much larger battery – 5,100mAh – than Samsung’s latest foldable, the Samsung Galaxy Z Fold 6, which has only a 4,400mAh cell despite being over 20 percent thicker. It also has 16GB of RAM, the latest Qualcomm Snapdragon 8 Gen 3 chip and six Leica-branded cameras.
Xiaomi says the significant slimming was achieved by switching to proprietary carbon fiber materials for several internal components, most notably the hinge.
I find the hinge a bit looser than Samsung’s rock-solid one, but Xiaomi’s still stays in place at most angles.
The phone also has an IPX8 water resistance rating, which means it can withstand splashes of water.
Software and features
The Mix Fold 4 runs Android 14 with Xiaomi’s HyperOS software, but since the phone is currently only sold in China, the software does not come with Google apps.
These can be installed, but the phone lacks native support for Google Assistant and Android Auto. Google Pay doesn’t work either. Other Google apps and services work perfectly.
There isn’t much specific software for the Mix Fold 4, as HyperOS behaves largely the same as on a regular phone. That’s not a bad thing, as HyperOS runs quickly and smoothly, but Samsung and Oppo add additional features to the software for their foldable phones to make the most of the larger screen.
Performance and battery life
The Mix Fold 4’s quad camera system is good for a foldable phone. The main camera captures shots with excellent dynamic range and detail, while the two zoom lenses offer more versatility, with focal lengths of 75mm and 115mm.
I find the zoom lenses to be significantly superior to the cameras on Samsung’s foldables and even the iPhone’s “Prism” zoom lens. But they fall far short of the high standards set by Xiaomi itself and Vivo with the two companies’ latest “Ultra” slab phones, which feature the two best cameras in phones currently available.
I also find Xiaomi’s color science to be inconsistent between lenses, but that’s hair-splitting that only concerns mobile photography experts. For most, the cameras are more than good enough.
The performance of the rest of the phone is at a high level thanks to the latest chips and plenty of RAM. Battery life is also satisfactory – the phone will almost certainly last all day even with intensive use.
Diploma
The Mix Fold 4’s biggest weakness is its thin and light build, which makes the barely a month old Galaxy Z Fold 6 feel clunky and bulky. Other than that, the display, performance and cameras are all good, but nothing we haven’t seen from other foldable phones before.
The Mix Fold 4 is currently only sold in China and costs 8,999 yuan ($1,260).
