Between the Galaxy S25 Ultra and Xiaomi 15, the Galaxy S25 Ultra comes out ahead in main camera and pixel density, while the Xiaomi 15 wins on wireless charging and front camera. Overall, the Galaxy S25 Ultra scores 73.9 and the Xiaomi 15 scores 70 on our Mars Score.
Which should you buy?
The Galaxy S25 Ultra edges ahead on the Mars Score (73.9 vs 70), but the 3.9-point gap is small enough that the right pick comes down to which spec advantages matter to you.
Pick the Galaxy S25 Ultra if you photograph or shoot video regularly and want the better imaging pipeline of the two. The biggest gaps in its favor are main camera, pixel density, screen size, among others.
Pick the Xiaomi 15 if you photograph or shoot video regularly and want the better imaging pipeline of the two. Its strongest claims are wireless charging, front camera, wired charging, among others.
Both ship with comparable ram, 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 Samsung - Galaxy S25 Ultra wins
- ▲Main camera — 300.00% more. 200 MP vs 50 MP.
- ▲Pixel density — 8.91% more. 501 ppi vs 460 ppi.
- ▲Screen size — 8.49% more. 6.9 " vs 6.36 ".
- ▲Promised OS updates: 7 (vs 4).
Why Xiaomi 15 wins
- ▲Wireless charging — 233.33% more. 50 W vs 15 W.
- ▲Front camera — 166.67% more. 32 MP vs 12 MP.
- ▲Wired charging — 100.00% more. 90 W vs 45 W.
- ▲Weight — 26.00 g less. 192 vs 218.
- ▲AnTuTu — 24.65% more. 2680000 vs 2150000.
- ▲Battery capacity — 8.00% more. 5400 mAh vs 5000 mAh.
Spec comparison
Design
| Spec | Samsung - Galaxy S25 Ultra | Xiaomi 15 |
|---|---|---|
| Weight | 218 g | 192 glead |
| Thickness | 8.2 mm | 8.1 mmlead |
| Water resistanceⓘ | IP68 | IP68 |
| Form factor | bar | bar |
Display
| Spec | Samsung - Galaxy S25 Ultra | Xiaomi 15 |
|---|---|---|
| Screen sizeⓘ | 6.9 "lead | 6.36 " |
| Pixel densityⓘ | 501 ppilead | 460 ppi |
| Refresh rateⓘ | 120 Hz | 120 Hz |
| Peak brightnessⓘ | 2600 nits | 3200 nitslead |
Performance
Cameras
| Spec | Samsung - Galaxy S25 Ultra | Xiaomi 15 |
|---|---|---|
| Main cameraⓘ | 200 MPlead | 50 MP |
| Front camera | 12 MP | 32 MPlead |
| Optical image stabilizationⓘ | true | true |
Battery
| Spec | Samsung - Galaxy S25 Ultra | Xiaomi 15 |
|---|---|---|
| Battery capacity | 5000 mAh | 5400 mAhlead |
| Wired chargingⓘ | 45 W | 90 Wlead |
| Wireless chargingⓘ | 15 W | 50 Wlead |
Connectivity
| Spec | Samsung - Galaxy S25 Ultra | Xiaomi 15 |
|---|---|---|
| 5G supportⓘ | true | true |
| Headphone jack | false | false |
| microSD slot | false | false |
Operating System
| Spec | Samsung - Galaxy S25 Ultra | Xiaomi 15 |
|---|---|---|
| OS | Android | Android |
| Promised OS updates | 7 yearslead | 4 years |
Frequently asked
Which has better battery, Galaxy S25 Ultra or Xiaomi 15?+
Xiaomi 15 has 8.0% more battery — 5000 mAh vs 5400 mAh.
Which is lighter, Galaxy S25 Ultra or Xiaomi 15?+
Xiaomi 15 is 26g lighter — 218g vs 192g.
Is Galaxy S25 Ultra waterproof?+
Galaxy S25 Ultra has an IP68 rating.
Does Xiaomi 15 support 5G?+
Yes, Xiaomi 15 supports 5G.
Which has a better camera, Galaxy S25 Ultra or Xiaomi 15?+
Galaxy S25 Ultra has a 200 MP main camera vs 50 MP.
Spec-level deep dives
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