Where they actually differ
The most decisive specs, ranked by how much they matter — before the full spec table.
| Spec | ASUS - Zenfone 11 Ultra | Xiaomi 15 |
|---|---|---|
| Wireless charging | 15 W | 50 W |
| Wired charging | 65 W | 90 W |
| RAM | 16 GB | 12 GB |
| Weight | 224 g | 192 g |
| AnTuTu | 2070000 | 2680000 |
| Refresh rate | 144 Hz | 120 Hz |
Between the Zenfone 11 Ultra and Xiaomi 15, the Zenfone 11 Ultra comes out ahead in ram / refresh rate, while the Xiaomi 15 wins on wireless charging / wired charging. Overall, the Zenfone 11 Ultra scores 69.2 and the Xiaomi 15 scores 69.8 on our Mars Score.
Which should you buy?
These two are nearly even on the Mars Score (69.2 vs 69.8). The decision is not about overall quality — both clear the bar — it is about which specific trade-offs fit your use.
Pick the Zenfone 11 Ultra 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 ram, refresh rate, screen size, among others. The single most decisive one: RAM — 33.33% more. 16 GB vs 12 GB.
Pick the Xiaomi 15 if you carry the device everywhere and weight or thickness has been the deciding factor before. Its strongest claims are wireless charging, wired charging, weight, among others. The single most decisive one: Wireless charging — 233.33% more. 50 W vs 15 W.
Both ship with comparable main camera, 5g support, water resistance, 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: ASUS - Zenfone 11 Ultra or Xiaomi 15?
Xiaomi 15 leads the current Mars Score by 0.6 points.The more useful decision is the trade-off behind that result: compare screen size, ram, pixel density, battery capacity against the way you will actually use the product.
Choose ASUS - Zenfone 11 Ultra if…
ASUS - Zenfone 11 Ultra has the measurable edge on ram gb, refresh rate hz, screen size in.
Choose Xiaomi 15 if…
Xiaomi 15 has the measurable edge on wireless charging w, wired charging w, weight g.
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 ASUS - Zenfone 11 Ultra wins
- ▲RAM — 33.33% more. 16 GB vs 12 GB.
- ▲Refresh rate — 20.00% more. 144 Hz vs 120 Hz.
- ▲Screen size — 6.60% more. 6.78 " vs 6.36 ".
- ▲Battery capacity — 1.85% more. 5500 mAh vs 5400 mAh.
Why Xiaomi 15 wins
- ▲Wireless charging — 233.33% more. 50 W vs 15 W.
- ▲Wired charging — 38.46% more. 90 W vs 65 W.
- ▲Weight — 32.00 g less. 192 vs 224.
- ▲AnTuTu — 29.47% more. 2680000 vs 2070000.
- ▲Pixel density — 18.56% more. 460 ppi vs 388 ppi.
- ▲Promised OS updates: 4 (vs 2).
Spec comparison
Design
| Spec | ASUS - Zenfone 11 Ultra | Xiaomi 15 |
|---|---|---|
| Weight | 224 g | 192 glead |
| Thickness | 8.9 mm | 8.1 mmlead |
| Water resistanceⓘ | IP68 | IP68 |
| Form factor | bar | bar |
Display
| Spec | ASUS - Zenfone 11 Ultra | Xiaomi 15 |
|---|---|---|
| Screen size | 6.78 "lead | 6.36 " |
| Pixel densityⓘ | 388 ppi | 460 ppilead |
| Refresh rateⓘ | 144 Hzlead | 120 Hz |
| Peak brightnessⓘ | 2500 nits | 3200 nitslead |
Performance
| Spec | ASUS - Zenfone 11 Ultra | Xiaomi 15 |
|---|---|---|
| RAMⓘ | 16 GBlead | 12 GB |
| Storageⓘ | 512 GBlead | 256 GB |
| AnTuTuⓘ | 2070000 | 2680000lead |
| CPU total clockⓘ | 21.4 GHz | 22.8 GHzlead |
Cameras
| Spec | ASUS - Zenfone 11 Ultra | Xiaomi 15 |
|---|---|---|
| Main cameraⓘ | 50 MP | 50 MP |
| Front camera | 32 MP | 32 MP |
| Optical image stabilizationⓘ | true | true |
Battery
| Spec | ASUS - Zenfone 11 Ultra | Xiaomi 15 |
|---|---|---|
| Battery capacityⓘ | 5500 mAhlead | 5400 mAh |
| Wired chargingⓘ | 65 W | 90 Wlead |
| Wireless chargingⓘ | 15 W | 50 Wlead |
Connectivity
| Spec | ASUS - Zenfone 11 Ultra | Xiaomi 15 |
|---|---|---|
| 5G supportⓘ | true | true |
| Headphone jack | false | false |
| microSD slot | false | false |
Operating System
| Spec | ASUS - Zenfone 11 Ultra | Xiaomi 15 |
|---|---|---|
| OS | Android | Android |
| Promised OS updates | 2 years | 4 yearslead |
Frequently asked
Which has better battery, Zenfone 11 Ultra or Xiaomi 15?+
Zenfone 11 Ultra has 1.9% more battery — 5500 mAh vs 5400 mAh.
Which is lighter, Zenfone 11 Ultra or Xiaomi 15?+
Xiaomi 15 is 32g lighter — 224g vs 192g.
Is Zenfone 11 Ultra waterproof?+
Zenfone 11 Ultra has an IP68 rating.
Does Xiaomi 15 support 5G?+
Yes, Xiaomi 15 supports 5G.
Which has more RAM, Zenfone 11 Ultra or Xiaomi 15?+
Zenfone 11 Ultra offers 16GB of RAM.
Which has a better camera, Zenfone 11 Ultra or Xiaomi 15?+
Xiaomi 15 has a 50 MP main camera vs 50 MP.