ASUS Zenfone 4 Pro ZS551KL vs Vivo iQOO 15 Ultra
The ASUS Zenfone 4 Pro ZS551KL (2017) runs on the Qualcomm Snapdragon 835, while the Vivo iQOO 15 Ultra (2026) runs on the Qualcomm Snapdragon 8 Elite Gen 5; launch prices were $599 and $799. By overall MobileRank rating, the Vivo iQOO 15 Ultra leads — 89/100 vs 31/100 (a 58-point difference). Key differences: the Vivo iQOO 15 Ultra has the bigger battery (7400 mAh vs 3600); the main camera is 12 MP vs 50 MP; the Vivo iQOO 15 Ultra is faster in AnTuTu (4,602,290 vs 438,016); the ASUS Zenfone 4 Pro ZS551KL is noticeably lighter (175g vs 227g).
Profile comparison
Category scores
ASUS Zenfone 4 Pro ZS551KL
Vivo iQOO 15 Ultra
What makes ASUS Zenfone 4 Pro ZS551KL better?
- Lighter: 175g vs 227g
- Cheaper at launch: $599 vs $799
- Better portability (78/100 vs 35/100)
What makes Vivo iQOO 15 Ultra better?
- Higher AnTuTu: 4602290 vs 438016
- Better Geekbench Single: 3639 vs 427
- Better Geekbench Multi: 11047 vs 1500
- Bigger battery: 7400 vs 3600 mAh
- Faster charging: 120W vs 18W
- Better main camera: 50MP vs 12MP
- Higher refresh rate: 144Hz vs 60Hz
- Higher performance (99/100 vs 33/100)
- Better camera (78/100 vs 17/100)
- Longer battery life (92/100 vs 13/100)
- Better display (99/100 vs 56/100)
Comparison verdict
Comparing the ASUS Zenfone 4 Pro ZS551KL vs the Vivo iQOO 15 Ultra, the Vivo iQOO 15 Ultra scores 58 points higher (89/100 vs 31/100). In the "performance" category, the Vivo iQOO 15 Ultra leads (99/100 vs 33/100). In the "camera" category, the Vivo iQOO 15 Ultra leads (78/100 vs 17/100). In the "battery" category, the Vivo iQOO 15 Ultra leads (92/100 vs 13/100). Value score: ASUS Zenfone 4 Pro ZS551KL — 0/100, Vivo iQOO 15 Ultra — 92/100; it shows how far a model sits above or below the usual level for its price, and is not part of the overall rating. In the "performance" category, the Vivo iQOO 15 Ultra significantly outperforms the ASUS Zenfone 4 Pro ZS551KL (99/100 vs 33/100). In the "display" category, the Vivo iQOO 15 Ultra significantly outperforms the ASUS Zenfone 4 Pro ZS551KL (99/100 vs 56/100). In the "camera" category, the Vivo iQOO 15 Ultra significantly outperforms the ASUS Zenfone 4 Pro ZS551KL (78/100 vs 17/100). In the "battery" category, the Vivo iQOO 15 Ultra significantly outperforms the ASUS Zenfone 4 Pro ZS551KL (92/100 vs 13/100). In the "portability" category, the ASUS Zenfone 4 Pro ZS551KL significantly outperforms the Vivo iQOO 15 Ultra (78/100 vs 35/100).
Specs comparison
| Specification | ASUS Zenfone 4 Pro ZS551KL | Vivo iQOO 15 Ultra | |
|---|---|---|---|
| Processor | Qualcomm Snapdragon 835 | Qualcomm Snapdragon 8 Elite Gen 5 | |
| AnTuTu | 438016 | 4602290 | |
| Geekbench Single | 427 | 3639 | |
| Geekbench Multi | 1500 | 11047 | |
| Display | 5.5" AMOLED | 6.8" LTPO AMOLED | |
| Resolution | 1080x1920 | 1440x3168 | |
| Refresh rate | 60 Hz | 144 Hz | |
| Battery | 3600 mAh | 7400 mAh | |
| Charging | 18W | 120W | |
| Wireless charging | 0W | 50W | |
| Main camera | 12 MP | 50 MP | |
| Ultrawide | 0 MP | 50 MP | |
| Telephoto | 16 MP | 50 MP | |
| Front camera | 8 MP | 32 MP | |
| RAM | 6GB | 12GB / 16GB / 24GB | |
| Storage | 64GB / 128GB | 256GB / 512GB / 1TB | |
| OS | Android 7.1.1 Nougat | Android 16 | |
| Brightness (peak) | — | 8000 nits | |
| NFC | yes | yes | |
| Protection | — | IP68 | |
| Dimensions | 156.9×75.6×7.6 mm | 163.7×76.8×8.7 mm | |
| Weight | 175 g | 227 g | |
| Launch price | $599 | $799 |
Camera comparison
ASUS Zenfone 4 Pro ZS551KL
- Main: 12MP f/1.7
- Telephoto: 16MP
- Front: 8MP
Vivo iQOO 15 Ultra
- Main: 50MP f/1.9
- Ultrawide: 50MP
- Telephoto: 50MP
- Front: 32MP
Display comparison
ASUS Zenfone 4 Pro ZS551KL
- 5.5" AMOLED
- Resolution: 1080x1920
- Refresh rate: 60 Hz
Vivo iQOO 15 Ultra
- 6.8" LTPO AMOLED
- Resolution: 1440x3168
- Refresh rate: 144 Hz
Battery and charging
ASUS Zenfone 4 Pro ZS551KL
- 3600 mAh
- Wired: 18W
- No wireless charging
Vivo iQOO 15 Ultra
- 7400 mAh
- Wired: 120W
- Wireless: 50W
Overall performance score
We compared ASUS Zenfone 4 Pro ZS551KL and Vivo iQOO 15 Ultra, covering their specs and all relevant benchmarks.
Vivo iQOO 15 Ultra leads ASUS Zenfone 4 Pro ZS551KL by 90.5% in our overall performance rating.
Benchmarks
Launch prices and where to check today's
Launch price difference: $200. ASUS Zenfone 4 Pro ZS551KL was $200 cheaper at launch.
Detailed category analysis
performance
In the "performance" category, the Vivo iQOO 15 Ultra significantly outperforms the ASUS Zenfone 4 Pro ZS551KL (99/100 vs 33/100).
display
In the "display" category, the Vivo iQOO 15 Ultra significantly outperforms the ASUS Zenfone 4 Pro ZS551KL (99/100 vs 56/100).
camera
In the "camera" category, the Vivo iQOO 15 Ultra significantly outperforms the ASUS Zenfone 4 Pro ZS551KL (78/100 vs 17/100).
battery
In the "battery" category, the Vivo iQOO 15 Ultra significantly outperforms the ASUS Zenfone 4 Pro ZS551KL (92/100 vs 13/100).
portability
In the "portability" category, the ASUS Zenfone 4 Pro ZS551KL significantly outperforms the Vivo iQOO 15 Ultra (78/100 vs 35/100).
Frequently asked questions
Which is better: the ASUS Zenfone 4 Pro ZS551KL or the Vivo iQOO 15 Ultra?
The Vivo iQOO 15 Ultra significantly outperforms the ASUS Zenfone 4 Pro ZS551KL by 58 points (89/100 vs 31/100).
What is the rating of the ASUS Zenfone 4 Pro ZS551KL and the Vivo iQOO 15 Ultra?
The ASUS Zenfone 4 Pro ZS551KL has a MobileRank rating of 31/100, the Vivo iQOO 15 Ultra — 89/100.
Which has the better camera: the ASUS Zenfone 4 Pro ZS551KL or the Vivo iQOO 15 Ultra?
The Vivo iQOO 15 Ultra leads on camera score (78/100 vs 17/100).
Which is more powerful: the ASUS Zenfone 4 Pro ZS551KL or the Vivo iQOO 15 Ultra?
The Vivo iQOO 15 Ultra leads on performance (99/100 vs 33/100).
Should you choose the ASUS Zenfone 4 Pro ZS551KL over the Vivo iQOO 15 Ultra?
The Vivo iQOO 15 Ultra is a better fit for gamers and power users, those who care about battery life, budget-conscious buyers.