Between the ROG Phone 9 and Xiaomi 15 Ultra, the ROG Phone 9 comes out ahead in refresh rate and weight, while the Xiaomi 15 Ultra wins on wireless charging and wired charging. Overall, the ROG Phone 9 scores 75.1 and the Xiaomi 15 Ultra scores 73.8 on our Mars Score.
Which should you buy?
These two are nearly even on the Mars Score (75.1 vs 73.8). The decision isn't about overall quality — both clear the bar — it's about which specific trade-offs fit your use.
Pick the ROG Phone 9 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 refresh rate, weight, headphone jack, among others.
Pick the Xiaomi 15 Ultra 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 wireless charging, wired charging, pixel density, among others.
Both ship with comparable ram, main camera, 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 ASUS - ROG Phone 9 wins
- ▲Refresh rate — 54.17% more. 185 Hz vs 120 Hz.
- ▲Weight — 2.00 g less. 227 vs 229.
- ▲Has Headphone jack.
- ▲Screen size — 0.74% more. 6.78 " vs 6.73 ".
Why Xiaomi 15 Ultra wins
- ▲Wireless charging — 433.33% more. 80 W vs 15 W.
- ▲Wired charging — 38.46% more. 90 W vs 65 W.
- ▲Pixel density — 34.54% more. 522 ppi vs 388 ppi.
- ▲AnTuTu — 5.43% more. 2720000 vs 2580000.
- ▲Battery capacity — 3.45% more. 6000 mAh vs 5800 mAh.
- ▲Promised OS updates: 4 (vs 3).
Spec comparison
Design
| Spec | ASUS - ROG Phone 9 | Xiaomi 15 Ultra |
|---|---|---|
| Weight | 227 glead | 229 g |
| Thickness | 8.9 mmlead | 9.4 mm |
| Water resistanceⓘ | IP68 | IP68 |
| Form factor | bar | bar |
Display
| Spec | ASUS - ROG Phone 9 | Xiaomi 15 Ultra |
|---|---|---|
| Screen sizeⓘ | 6.78 "lead | 6.73 " |
| Pixel densityⓘ | 388 ppi | 522 ppilead |
| Refresh rateⓘ | 185 Hzlead | 120 Hz |
| Peak brightnessⓘ | 2500 nits | 3200 nitslead |
Performance
Cameras
| Spec | ASUS - ROG Phone 9 | Xiaomi 15 Ultra |
|---|---|---|
| Main cameraⓘ | 50 MP | 50 MP |
| Front camera | 32 MP | 32 MP |
| Optical image stabilizationⓘ | true | true |
Battery
| Spec | ASUS - ROG Phone 9 | Xiaomi 15 Ultra |
|---|---|---|
| Battery capacity | 5800 mAh | 6000 mAhlead |
| Wired chargingⓘ | 65 W | 90 Wlead |
| Wireless chargingⓘ | 15 W | 80 Wlead |
Connectivity
| Spec | ASUS - ROG Phone 9 | Xiaomi 15 Ultra |
|---|---|---|
| 5G supportⓘ | true | true |
| Headphone jack | truelead | false |
| microSD slot | false | false |
Operating System
| Spec | ASUS - ROG Phone 9 | Xiaomi 15 Ultra |
|---|---|---|
| OS | Android | Android |
| Promised OS updates | 3 years | 4 yearslead |
Frequently asked
Which has better battery, ROG Phone 9 or Xiaomi 15 Ultra?+
Xiaomi 15 Ultra has 3.4% more battery — 5800 mAh vs 6000 mAh.
Which is lighter, ROG Phone 9 or Xiaomi 15 Ultra?+
ROG Phone 9 is 2g lighter — 227g vs 229g.
Is ROG Phone 9 waterproof?+
ROG Phone 9 has an IP68 rating.
Does Xiaomi 15 Ultra support 5G?+
Yes, Xiaomi 15 Ultra supports 5G.
Which has a better camera, ROG Phone 9 or Xiaomi 15 Ultra?+
Xiaomi 15 Ultra has a 50 MP main camera vs 50 MP.
Spec-level deep dives
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