Between the Xiaomi 15 Ultra and MIX Fold 4, the Xiaomi 15 Ultra comes out ahead in front camera and wireless charging, while the MIX Fold 4 wins on screen size and weight. Overall, the Xiaomi 15 Ultra scores 73.8 and the MIX Fold 4 scores 71.4 on our Mars Score.
Which should you buy?
These two are nearly even on the Mars Score (73.8 vs 71.4). The decision isn't about overall quality — both clear the bar — it's about which specific trade-offs fit your use.
Pick the Xiaomi 15 Ultra if you photograph or shoot video regularly and want the better imaging pipeline of the two. The biggest gaps in its favor are front camera, wireless charging, wired charging, among others.
Pick the MIX Fold 4 if the display is what you stare at all day — refresh rate, brightness, or sharpness is where the difference will be most visible. Its strongest claims are screen size, weight, water resistance.
Both ship with comparable ram, main camera, refresh rate, so those specs don't separate the two — focus on the differences below.
Bottom line: there is no wrong answer here — match the spec advantages to how you actually use the product. The Mars Score parity tells you both are well-rounded; the differences are about trade-offs, not quality.
Why Xiaomi 15 Ultra wins
- ▲Front camera — 60.00% more. 32 MP vs 20 MP.
- ▲Wireless charging — 60.00% more. 80 W vs 50 W.
- ▲Wired charging — 34.33% more. 90 W vs 67 W.
- ▲AnTuTu — 33.33% more. 2720000 vs 2040000.
- ▲Pixel density — 29.85% more. 522 ppi vs 402 ppi.
- ▲Battery capacity — 17.65% more. 6000 mAh vs 5100 mAh.
Why Xiaomi - MIX Fold 4 wins
- ▲Screen size — 18.57% more. 7.98 " vs 6.73 ".
- ▲Weight — 3.00 g less. 226 vs 229.
- ▲Water resistance: IPX8 (vs IP68).
Spec comparison
Design
| Spec | Xiaomi 15 Ultra | Xiaomi - MIX Fold 4 |
|---|---|---|
| Weight | 229 g | 226 glead |
| Thickness | 9.4 mmlead | 9.47 mm |
| Water resistanceⓘ | IP68 | IPX8lead |
| Form factor | bar | foldable_booklead |
Display
| Spec | Xiaomi 15 Ultra | Xiaomi - MIX Fold 4 |
|---|---|---|
| Screen sizeⓘ | 6.73 " | 7.98 "lead |
| Pixel densityⓘ | 522 ppilead | 402 ppi |
| Refresh rateⓘ | 120 Hz | 120 Hz |
| Peak brightnessⓘ | 3200 nitslead | 3000 nits |
Performance
Cameras
| Spec | Xiaomi 15 Ultra | Xiaomi - MIX Fold 4 |
|---|---|---|
| Main cameraⓘ | 50 MP | 50 MP |
| Front camera | 32 MPlead | 20 MP |
| Optical image stabilizationⓘ | true | true |
Battery
| Spec | Xiaomi 15 Ultra | Xiaomi - MIX Fold 4 |
|---|---|---|
| Battery capacity | 6000 mAhlead | 5100 mAh |
| Wired chargingⓘ | 90 Wlead | 67 W |
| Wireless chargingⓘ | 80 Wlead | 50 W |
Connectivity
| Spec | Xiaomi 15 Ultra | Xiaomi - MIX Fold 4 |
|---|---|---|
| 5G supportⓘ | true | true |
| Headphone jack | false | false |
| microSD slot | false | false |
Operating System
| Spec | Xiaomi 15 Ultra | Xiaomi - MIX Fold 4 |
|---|---|---|
| OS | Android | Android |
| Promised OS updates | 4 years | 4 years |
Frequently asked
Which has better battery, Xiaomi 15 Ultra or MIX Fold 4?+
Xiaomi 15 Ultra has 17.6% more battery — 6000 mAh vs 5100 mAh.
Which is lighter, Xiaomi 15 Ultra or MIX Fold 4?+
MIX Fold 4 is 3g lighter — 229g vs 226g.
Is Xiaomi 15 Ultra waterproof?+
Xiaomi 15 Ultra has an IP68 rating.
Does MIX Fold 4 support 5G?+
Yes, MIX Fold 4 supports 5G.
Which has a better camera, Xiaomi 15 Ultra or MIX Fold 4?+
MIX Fold 4 has a 50 MP main camera vs 50 MP.
Spec-level deep dives
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