Between the OnePlus Open 2 and Xiaomi 15, the OnePlus Open 2 comes out ahead in ram and screen size, while the Xiaomi 15 wins on weight and pixel density. Overall, the OnePlus Open 2 scores 74.5 and the Xiaomi 15 scores 70 on our Mars Score.
Which should you buy?
The OnePlus Open 2 edges ahead on the Mars Score (74.5 vs 70), but the 4.5-point gap is small enough that the right pick comes down to which spec advantages matter to you.
Pick the OnePlus Open 2 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 ram, screen size, battery capacity.
Pick the Xiaomi 15 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 weight, pixel density, wired charging.
Both ship with comparable main camera, refresh rate, 5g support, 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 OnePlus Open 2 wins
- ▲RAM — 33.33% more. 16 GB vs 12 GB.
- ▲Screen size — 25.79% more. 8.0 " vs 6.36 ".
- ▲Battery capacity — 5.56% more. 5700 mAh vs 5400 mAh.
Why Xiaomi 15 wins
- ▲Weight — 47.00 g less. 192 vs 239.
- ▲Pixel density — 14.43% more. 460 ppi vs 402 ppi.
- ▲Wired charging — 12.50% more. 90 W vs 80 W.
Spec comparison
Design
| Spec | OnePlus Open 2 | Xiaomi 15 |
|---|---|---|
| Weight | 239 g | 192 glead |
| Thickness | 11.7 mm | 8.1 mmlead |
| Water resistanceⓘ | IP68 | IP68 |
| Form factor | foldable_booklead | bar |
Display
| Spec | OnePlus Open 2 | Xiaomi 15 |
|---|---|---|
| Screen sizeⓘ | 8.0 "lead | 6.36 " |
| Pixel densityⓘ | 402 ppi | 460 ppilead |
| Refresh rateⓘ | 120 Hz | 120 Hz |
| Peak brightnessⓘ | 4500 nitslead | 3200 nits |
Performance
Cameras
| Spec | OnePlus Open 2 | Xiaomi 15 |
|---|---|---|
| Main cameraⓘ | 50 MP | 50 MP |
| Front camera | 32 MP | 32 MP |
| Optical image stabilizationⓘ | true | true |
Battery
| Spec | OnePlus Open 2 | Xiaomi 15 |
|---|---|---|
| Battery capacity | 5700 mAhlead | 5400 mAh |
| Wired chargingⓘ | 80 W | 90 Wlead |
| Wireless chargingⓘ | 50 W | 50 W |
Connectivity
| Spec | OnePlus Open 2 | Xiaomi 15 |
|---|---|---|
| 5G supportⓘ | true | true |
| Headphone jack | false | false |
| microSD slot | false | false |
Operating System
| Spec | OnePlus Open 2 | Xiaomi 15 |
|---|---|---|
| OS | Android | Android |
| Promised OS updates | 4 years | 4 years |
Frequently asked
Which has better battery, OnePlus Open 2 or Xiaomi 15?+
OnePlus Open 2 has 5.6% more battery — 5700 mAh vs 5400 mAh.
Which is lighter, OnePlus Open 2 or Xiaomi 15?+
Xiaomi 15 is 47g lighter — 239g vs 192g.
Is OnePlus Open 2 waterproof?+
OnePlus Open 2 has an IP68 rating.
Does Xiaomi 15 support 5G?+
Yes, Xiaomi 15 supports 5G.
Which has more RAM, OnePlus Open 2 or Xiaomi 15?+
OnePlus Open 2 offers 16GB of RAM.
Which has a better camera, OnePlus Open 2 or Xiaomi 15?+
Xiaomi 15 has a 50 MP main camera vs 50 MP.
Spec-level deep dives
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