Between the Phone (3a) and Xiaomi 15, the Phone (3a) comes out ahead in screen size, while the Xiaomi 15 wins on antutu and wired charging. Overall, the Phone (3a) scores 62.5 and the Xiaomi 15 scores 70 on our Mars Score.
Which should you buy?
The Xiaomi 15 edges ahead on the Mars Score (62.5 vs 70), but the 7.5-point gap is small enough that the right pick comes down to which spec advantages matter to you.
Pick the Phone (3a) 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.
Pick the Xiaomi 15 if you push the hardware — gaming, on-device AI, heavy multitasking — and the extra compute headroom is worth the trade-offs. Its strongest claims are antutu, wired charging, ram, among others.
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: the Xiaomi 15 is the safer default. The other model is the right choice only when its specific advantages line up with your priorities.
Why Nothing - Phone (3a) wins
- ▲Screen size — 6.45% more. 6.77 " vs 6.36 ".
Why Xiaomi 15 wins
- ▲AnTuTu — 226.83% more. 2680000 vs 820000.
- ▲Wired charging — 80.00% more. 90 W vs 50 W.
- ▲RAM — 50.00% more. 12 GB vs 8 GB.
- ▲Pixel density — 18.86% more. 460 ppi vs 387 ppi.
- ▲Weight — 9.00 g less. 192 vs 201.
- ▲Battery capacity — 8.00% more. 5400 mAh vs 5000 mAh.
- ▲Water resistance: IP68 (vs IP64).
- ▲Promised OS updates: 4 (vs 3).
Spec comparison
Design
| Spec | Nothing - Phone (3a) | Xiaomi 15 |
|---|---|---|
| Weight | 201 g | 192 glead |
| Thickness | 8.4 mm | 8.1 mmlead |
| Water resistanceⓘ | IP64 | IP68lead |
| Form factor | bar | bar |
Display
| Spec | Nothing - Phone (3a) | Xiaomi 15 |
|---|---|---|
| Screen sizeⓘ | 6.77 "lead | 6.36 " |
| Pixel densityⓘ | 387 ppi | 460 ppilead |
| Refresh rateⓘ | 120 Hz | 120 Hz |
| Peak brightnessⓘ | 3000 nits | 3200 nitslead |
Performance
Cameras
| Spec | Nothing - Phone (3a) | Xiaomi 15 |
|---|---|---|
| Main cameraⓘ | 50 MP | 50 MP |
| Front camera | 32 MP | 32 MP |
| Optical image stabilizationⓘ | true | true |
Battery
| Spec | Nothing - Phone (3a) | Xiaomi 15 |
|---|---|---|
| Battery capacity | 5000 mAh | 5400 mAhlead |
| Wired chargingⓘ | 50 W | 90 Wlead |
| Wireless chargingⓘ | 0 W | 50 Wlead |
Connectivity
| Spec | Nothing - Phone (3a) | Xiaomi 15 |
|---|---|---|
| 5G supportⓘ | true | true |
| Headphone jack | false | false |
| microSD slot | false | false |
Operating System
| Spec | Nothing - Phone (3a) | Xiaomi 15 |
|---|---|---|
| OS | Android | Android |
| Promised OS updates | 3 years | 4 yearslead |
Frequently asked
Which has better battery, Phone (3a) or Xiaomi 15?+
Xiaomi 15 has 8.0% more battery — 5000 mAh vs 5400 mAh.
Which is lighter, Phone (3a) or Xiaomi 15?+
Xiaomi 15 is 9g lighter — 201g vs 192g.
Is Phone (3a) waterproof?+
Phone (3a) has an IP64 rating.
Does Xiaomi 15 support 5G?+
Yes, Xiaomi 15 supports 5G.
Which has more RAM, Phone (3a) or Xiaomi 15?+
Xiaomi 15 offers 12GB of RAM.
Which has a better camera, Phone (3a) or Xiaomi 15?+
Xiaomi 15 has a 50 MP main camera vs 50 MP.
Spec-level deep dives
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