Where they actually differ
The most decisive specs, ranked by how much they matter — before the full spec table.
| Spec | OnePlus Open 2 | Xiaomi 15 Ultra |
|---|---|---|
| Wireless charging | 50 W | 80 W |
| Pixel density | 402 ppi | 522 ppi |
| Screen size | 8.0 " | 6.73 " |
| Wired charging | 80 W | 90 W |
| Weight | 239 g | 229 g |
| Battery capacity | 5700 mAh | 6000 mAh |
Between the OnePlus Open 2 and Xiaomi 15 Ultra, the OnePlus Open 2 comes out ahead in screen size, while the Xiaomi 15 Ultra wins on wireless charging / pixel density. Overall, the OnePlus Open 2 scores 71.8 and the Xiaomi 15 Ultra scores 71.5 on our Mars Score.
Which should you buy?
These two are nearly even on the Mars Score (71.8 vs 71.5). The decision is not about overall quality — both clear the bar — it is about which specific trade-offs fit your use.
Pick the OnePlus Open 2 if the display is what you stare at all day — refresh rate, brightness, or sharpness is where the difference will be most visible. The biggest gaps in its favor are screen size. The single most decisive one: Screen size — 18.87% more. 8.0 " vs 6.73 ".
Pick the Xiaomi 15 Ultra if you care most about wireless charging / pixel density. Its strongest claims are wireless charging, pixel density, wired charging, among others. The single most decisive one: Wireless charging — 60.00% more. 80 W vs 50 W.
Both ship with comparable ram, main camera, refresh rate, so those specs do not 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 says both are well-rounded; the differences are about trade-offs, not quality.
Which should you buy: OnePlus Open 2 or Xiaomi 15 Ultra?
OnePlus Open 2 leads the current Mars Score by 0.3 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 Open 2 if…
OnePlus Open 2 has the measurable edge on screen size in.
Choose Xiaomi 15 Ultra if…
Xiaomi 15 Ultra has the measurable edge on wireless charging w, pixel density ppi, wired charging w.
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 Open 2 wins
- ▲Screen size — 18.87% more. 8.0 " vs 6.73 ".
Why Xiaomi 15 Ultra wins
- ▲Wireless charging — 60.00% more. 80 W vs 50 W.
- ▲Pixel density — 29.85% more. 522 ppi vs 402 ppi.
- ▲Wired charging — 12.50% more. 90 W vs 80 W.
- ▲Weight — 10.00 g less. 229 vs 239.
- ▲Battery capacity — 5.26% more. 6000 mAh vs 5700 mAh.
- ▲AnTuTu — 1.49% more. 2720000 vs 2680000.
Spec comparison
Design
| Spec | OnePlus Open 2 | Xiaomi 15 Ultra |
|---|---|---|
| Weight | 239 g | 229 glead |
| Thickness | 11.7 mm | 9.4 mmlead |
| Water resistanceⓘ | IP68 | IP68 |
| Form factor | foldable_booklead | bar |
Display
| Spec | OnePlus Open 2 | Xiaomi 15 Ultra |
|---|---|---|
| Screen size | 8.0 "lead | 6.73 " |
| Pixel densityⓘ | 402 ppi | 522 ppilead |
| Refresh rateⓘ | 120 Hz | 120 Hz |
| Peak brightnessⓘ | 4500 nitslead | 3200 nits |
Performance
| Spec | OnePlus Open 2 | Xiaomi 15 Ultra |
|---|---|---|
| RAMⓘ | 16 GB | 16 GB |
| Storageⓘ | 512 GB | 512 GB |
| AnTuTuⓘ | 2680000 | 2720000lead |
| CPU total clockⓘ | 22.8 GHz | 22.8 GHz |
Cameras
| Spec | OnePlus Open 2 | Xiaomi 15 Ultra |
|---|---|---|
| Main cameraⓘ | 50 MP | 50 MP |
| Front camera | 32 MP | 32 MP |
| Optical image stabilizationⓘ | true | true |
Battery
| Spec | OnePlus Open 2 | Xiaomi 15 Ultra |
|---|---|---|
| Battery capacityⓘ | 5700 mAh | 6000 mAhlead |
| Wired chargingⓘ | 80 W | 90 Wlead |
| Wireless chargingⓘ | 50 W | 80 Wlead |
Connectivity
| Spec | OnePlus Open 2 | Xiaomi 15 Ultra |
|---|---|---|
| 5G supportⓘ | true | true |
| Headphone jack | false | false |
| microSD slot | false | false |
Operating System
| Spec | OnePlus Open 2 | Xiaomi 15 Ultra |
|---|---|---|
| OS | Android | Android |
| Promised OS updates | 4 years | 4 years |
Frequently asked
Which has better battery, OnePlus Open 2 or Xiaomi 15 Ultra?+
Xiaomi 15 Ultra has 5.3% more battery — 5700 mAh vs 6000 mAh.
Which is lighter, OnePlus Open 2 or Xiaomi 15 Ultra?+
Xiaomi 15 Ultra is 10g lighter — 239g vs 229g.
Is OnePlus Open 2 waterproof?+
OnePlus Open 2 has an IP68 rating.
Does Xiaomi 15 Ultra support 5G?+
Yes, Xiaomi 15 Ultra supports 5G.
Which has a better camera, OnePlus Open 2 or Xiaomi 15 Ultra?+
Xiaomi 15 Ultra has a 50 MP main camera vs 50 MP.