Between the Phone (3a) and OnePlus 15, the Phone (3a) comes out ahead in weight, while the OnePlus 15 wins on antutu and wired charging. Overall, the Phone (3a) scores 62.5 and the OnePlus 15 scores 78.4 on our Mars Score.
Which should you buy?
The OnePlus 15 is the clear pick on raw spec strength, leading by 15.9 points on the Mars Score. The margin is wide enough that the underdog only makes sense if its individual strengths line up with what you specifically need.
Pick the Phone (3a) if you carry the device everywhere and weight or thickness has been the deciding factor before. The biggest gaps in its favor are weight.
Pick the OnePlus 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 OnePlus 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
- ▲Weight — 10.00 g less. 201 vs 211.
Why OnePlus 15 wins
- ▲AnTuTu — 259.76% more. 2950000 vs 820000.
- ▲Wired charging — 140.00% more. 120 W vs 50 W.
- ▲RAM — 100.00% more. 16 GB vs 8 GB.
- ▲Battery capacity — 50.00% more. 7500 mAh vs 5000 mAh.
- ▲Pixel density — 16.28% more. 450 ppi vs 387 ppi.
- ▲Water resistance: IP69 (vs IP64).
- ▲Promised OS updates: 5 (vs 3).
- ▲Screen size — 0.15% more. 6.78 " vs 6.77 ".
Spec comparison
Design
| Spec | Nothing - Phone (3a) | OnePlus 15 |
|---|---|---|
| Weight | 201 glead | 211 g |
| Thickness | 8.4 mm | 8.3 mmlead |
| Water resistanceⓘ | IP64 | IP69lead |
| Form factor | bar | bar |
Display
| Spec | Nothing - Phone (3a) | OnePlus 15 |
|---|---|---|
| Screen sizeⓘ | 6.77 " | 6.78 "lead |
| Pixel densityⓘ | 387 ppi | 450 ppilead |
| Refresh rateⓘ | 120 Hz | 120 Hz |
| Peak brightnessⓘ | 3000 nits | 4500 nitslead |
Performance
Cameras
| Spec | Nothing - Phone (3a) | OnePlus 15 |
|---|---|---|
| Main cameraⓘ | 50 MP | 50 MP |
| Front camera | 32 MP | 32 MP |
| Optical image stabilizationⓘ | true | true |
Battery
| Spec | Nothing - Phone (3a) | OnePlus 15 |
|---|---|---|
| Battery capacity | 5000 mAh | 7500 mAhlead |
| Wired chargingⓘ | 50 W | 120 Wlead |
| Wireless chargingⓘ | 0 W | 50 Wlead |
Connectivity
| Spec | Nothing - Phone (3a) | OnePlus 15 |
|---|---|---|
| 5G supportⓘ | true | true |
| Headphone jack | false | false |
| microSD slot | false | false |
Operating System
| Spec | Nothing - Phone (3a) | OnePlus 15 |
|---|---|---|
| OS | Android | Android |
| Promised OS updates | 3 years | 5 yearslead |
Frequently asked
Which has better battery, Phone (3a) or OnePlus 15?+
OnePlus 15 has 50.0% more battery — 5000 mAh vs 7500 mAh.
Which is lighter, Phone (3a) or OnePlus 15?+
Phone (3a) is 10g lighter — 201g vs 211g.
Is Phone (3a) waterproof?+
Phone (3a) has an IP64 rating.
Does OnePlus 15 support 5G?+
Yes, OnePlus 15 supports 5G.
Which has more RAM, Phone (3a) or OnePlus 15?+
OnePlus 15 offers 16GB of RAM.
Which has a better camera, Phone (3a) or OnePlus 15?+
OnePlus 15 has a 50 MP main camera vs 50 MP.
Spec-level deep dives
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