Between the OnePlus Open 2 and ROG Phone 9 Pro, the OnePlus Open 2 comes out ahead in wireless charging and wired charging, while the ROG Phone 9 Pro wins on refresh rate and ram. Overall, the OnePlus Open 2 scores 74.5 and the ROG Phone 9 Pro scores 77.7 on our Mars Score.
Which should you buy?
The ROG Phone 9 Pro edges ahead on the Mars Score (74.5 vs 77.7), but the 3.2-point gap is small enough that the right pick comes down to which spec advantages matter to you.
Pick the OnePlus Open 2 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 wireless charging, wired charging, screen size, among others.
Pick the ROG Phone 9 Pro 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 refresh rate, ram, weight, among others.
Both ship with comparable main camera, 5g support, water resistance, 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 OnePlus Open 2 wins
- ▲Wireless charging — 233.33% more. 50 W vs 15 W.
- ▲Wired charging — 23.08% more. 80 W vs 65 W.
- ▲Screen size — 17.99% more. 8.0 " vs 6.78 ".
- ▲Pixel density — 3.61% more. 402 ppi vs 388 ppi.
- ▲Promised OS updates: 4 (vs 3).
Why ASUS - ROG Phone 9 Pro wins
- ▲Refresh rate — 54.17% more. 185 Hz vs 120 Hz.
- ▲RAM — 50.00% more. 24 GB vs 16 GB.
- ▲Weight — 12.00 g less. 227 vs 239.
- ▲Battery capacity — 1.75% more. 5800 mAh vs 5700 mAh.
- ▲Has Headphone jack.
Spec comparison
Design
| Spec | OnePlus Open 2 | ASUS - ROG Phone 9 Pro |
|---|---|---|
| Weight | 239 g | 227 glead |
| Thickness | 11.7 mm | 8.9 mmlead |
| Water resistanceⓘ | IP68 | IP68 |
| Form factor | foldable_booklead | bar |
Display
| Spec | OnePlus Open 2 | ASUS - ROG Phone 9 Pro |
|---|---|---|
| Screen sizeⓘ | 8.0 "lead | 6.78 " |
| Pixel densityⓘ | 402 ppilead | 388 ppi |
| Refresh rateⓘ | 120 Hz | 185 Hzlead |
| Peak brightnessⓘ | 4500 nitslead | 2500 nits |
Performance
Cameras
| Spec | OnePlus Open 2 | ASUS - ROG Phone 9 Pro |
|---|---|---|
| Main cameraⓘ | 50 MP | 50 MP |
| Front camera | 32 MP | 32 MP |
| Optical image stabilizationⓘ | true | true |
Battery
| Spec | OnePlus Open 2 | ASUS - ROG Phone 9 Pro |
|---|---|---|
| Battery capacity | 5700 mAh | 5800 mAhlead |
| Wired chargingⓘ | 80 Wlead | 65 W |
| Wireless chargingⓘ | 50 Wlead | 15 W |
Connectivity
| Spec | OnePlus Open 2 | ASUS - ROG Phone 9 Pro |
|---|---|---|
| 5G supportⓘ | true | true |
| Headphone jack | false | truelead |
| microSD slot | false | false |
Operating System
| Spec | OnePlus Open 2 | ASUS - ROG Phone 9 Pro |
|---|---|---|
| OS | Android | Android |
| Promised OS updates | 4 yearslead | 3 years |
Frequently asked
Which has better battery, OnePlus Open 2 or ROG Phone 9 Pro?+
ROG Phone 9 Pro has 1.8% more battery — 5700 mAh vs 5800 mAh.
Which is lighter, OnePlus Open 2 or ROG Phone 9 Pro?+
ROG Phone 9 Pro is 12g lighter — 239g vs 227g.
Is OnePlus Open 2 waterproof?+
OnePlus Open 2 has an IP68 rating.
Does ROG Phone 9 Pro support 5G?+
Yes, ROG Phone 9 Pro supports 5G.
Which has more RAM, OnePlus Open 2 or ROG Phone 9 Pro?+
ROG Phone 9 Pro offers 24GB of RAM.
Which has a better camera, OnePlus Open 2 or ROG Phone 9 Pro?+
ROG Phone 9 Pro has a 50 MP main camera vs 50 MP.
Spec-level deep dives
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