Where they actually differ
The most decisive specs, ranked by how much they matter — before the full spec table.
| Spec | OnePlus 15 | Xiaomi - MIX Fold 4 |
|---|---|---|
| Wired charging | 120 W | 67 W |
| Front camera | 32 MP | 20 MP |
| Battery capacity | 7500 mAh | 5100 mAh |
| AnTuTu | 2950000 | 2040000 |
| Screen size | 6.78 " | 7.98 " |
| Weight | 211 g | 226 g |
Between the OnePlus 15 and MIX Fold 4, the OnePlus 15 comes out ahead in wired charging / front camera, while the MIX Fold 4 wins on screen size / water resistance. Overall, the OnePlus 15 scores 76.7 and the MIX Fold 4 scores 69.5 on our Mars Score.
Which should you buy?
The OnePlus 15 edges ahead on the Mars Score (76.7 vs 69.5), but the 7.2-point gap is small enough that the right pick comes down to which spec advantages matter to you.
Pick the OnePlus 15 if your top frustration with your current device is running out of charge before the day ends — endurance is the lead spec here. The biggest gaps in its favor are wired charging, front camera, battery capacity, among others. The single most decisive one: Wired charging — 79.10% more. 120 W vs 67 W.
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, water resistance. The single most decisive one: Screen size — 17.70% more. 7.98 " vs 6.78 ".
Both ship with comparable ram, main camera, refresh rate, so those specs do not separate the two — focus on the differences below.
Bottom line: the OnePlus 15 is the safer default. The other model is the right choice only when its specific advantages line up with your priorities.
Which should you buy: OnePlus 15 or Xiaomi - MIX Fold 4?
OnePlus 15 leads the current Mars Score by 7.2 points.The more useful decision is the trade-off behind that result: compare screen size, pixel density, battery capacity against the way you will actually use the product.
Choose OnePlus 15 if…
OnePlus 15 has the measurable edge on wired charging w, front cam mp, battery capacity mah.
Choose Xiaomi - MIX Fold 4 if…
Xiaomi - MIX Fold 4 has the measurable edge on screen size in, ip rating.
This is a structured comparison of the published catalog values. It is not a claim of identical real-world performance across every workload; use the linked spec drill-downs and methodology page to inspect the inputs.
Why OnePlus 15 wins
- ▲Wired charging — 79.10% more. 120 W vs 67 W.
- ▲Front camera — 60.00% more. 32 MP vs 20 MP.
- ▲Battery capacity — 47.06% more. 7500 mAh vs 5100 mAh.
- ▲AnTuTu — 44.61% more. 2950000 vs 2040000.
- ▲Weight — 15.00 g less. 211 vs 226.
- ▲Pixel density — 11.94% more. 450 ppi vs 402 ppi.
- ▲Promised OS updates: 5 (vs 4).
Why Xiaomi - MIX Fold 4 wins
- ▲Screen size — 17.70% more. 7.98 " vs 6.78 ".
- ▲Water resistance: IPX8 (vs IP69).
Spec comparison
Design
| Spec | OnePlus 15 | Xiaomi - MIX Fold 4 |
|---|---|---|
| Weight | 211 glead | 226 g |
| Thickness | 8.3 mmlead | 9.47 mm |
| Water resistanceⓘ | IP69 | IPX8lead |
| Form factor | bar | foldable_booklead |
Display
| Spec | OnePlus 15 | Xiaomi - MIX Fold 4 |
|---|---|---|
| Screen size | 6.78 " | 7.98 "lead |
| Pixel densityⓘ | 450 ppilead | 402 ppi |
| Refresh rateⓘ | 120 Hz | 120 Hz |
| Peak brightnessⓘ | 4500 nitslead | 3000 nits |
Performance
| Spec | OnePlus 15 | Xiaomi - MIX Fold 4 |
|---|---|---|
| RAMⓘ | 16 GB | 16 GB |
| Storageⓘ | 512 GB | 512 GB |
| AnTuTuⓘ | 2950000lead | 2040000 |
| CPU total clockⓘ | 23.6 GHzlead | 21.0 GHz |
Cameras
| Spec | OnePlus 15 | Xiaomi - MIX Fold 4 |
|---|---|---|
| Main cameraⓘ | 50 MP | 50 MP |
| Front camera | 32 MPlead | 20 MP |
| Optical image stabilizationⓘ | true | true |
Battery
| Spec | OnePlus 15 | Xiaomi - MIX Fold 4 |
|---|---|---|
| Battery capacityⓘ | 7500 mAhlead | 5100 mAh |
| Wired chargingⓘ | 120 Wlead | 67 W |
| Wireless chargingⓘ | 50 W | 50 W |
Connectivity
| Spec | OnePlus 15 | Xiaomi - MIX Fold 4 |
|---|---|---|
| 5G supportⓘ | true | true |
| Headphone jack | false | false |
| microSD slot | false | false |
Operating System
| Spec | OnePlus 15 | Xiaomi - MIX Fold 4 |
|---|---|---|
| OS | Android | Android |
| Promised OS updates | 5 yearslead | 4 years |
Frequently asked
Which has better battery, OnePlus 15 or MIX Fold 4?+
OnePlus 15 has 47.1% more battery — 7500 mAh vs 5100 mAh.
Which is lighter, OnePlus 15 or MIX Fold 4?+
OnePlus 15 is 15g lighter — 211g vs 226g.
Is OnePlus 15 waterproof?+
OnePlus 15 has an IP69 rating.
Does MIX Fold 4 support 5G?+
Yes, MIX Fold 4 supports 5G.
Which has a better camera, OnePlus 15 or MIX Fold 4?+
MIX Fold 4 has a 50 MP main camera vs 50 MP.