Screen size
Zenfone 4 Pro ZS551KL5.5"
Zenfone 9Winner: 5.9"+6.8%
Quick verdict
Zenfone 9 leads the measured specs 17-3.
Measured wins
Zenfone 4 Pro ZS551KL
3
spec wins
Ties
3
equal specs
Zenfone 9
17
spec wins
Overall winner
Screen size
Technology
Zenfone 4 Pro ZS551KL
GSM / HSPA / LTE
Zenfone 9
GSM / HSPA / LTE / 5G
2G bands
Zenfone 4 Pro ZS551KL
GSM 850 / 900 / 1800 / 1900 - SIM 1 & SIM 2
Zenfone 9
GSM 850 / 900 / 1800 / 1900
3G bands
Zenfone 4 Pro ZS551KL
HSDPA 800 / 850 / 900 / 1700(AWS) / 1800 / 1900 / 2100
Zenfone 9
HSDPA 800 / 850 / 900 / 1700(AWS) / 1900 / 2100
4G bands
Zenfone 4 Pro ZS551KL
Resolution
Refresh rate
Peak brightness
Pixel density
CPU speed
RAM
equal specsStorage
Main camera
Front camera
Battery
Wired charging
Weight
Thickness
IP rating
Wi‑Fi
Bluetooth
USB
5G support
NFC
equal specs3.5mm jack
equal specsSD card
Stereo speakers
1, 2, 3, 4, 5, 7, 8, 17, 19, 20, 28, 38, 39, 40, 41 - Global, Taiwan, 1, 2, 3, 4, 5, 7, 8, 12, 17, 18, 19, 20, 26, 28, 29, 30, 38, 39, 41 - US, Canada, Brazil, 1, 2, 3, 4, 5, 7, 8, 12, 17, 18, 19, 20, 26, 28, 29, 30, 38, 39, 40, 41 - India
Zenfone 9
1, 2, 3, 4, 5, 7, 8, 12, 17, 18, 19, 20, 26, 28, 34, 38, 39, 40, 41, 42 - A version, 1, 2, 3, 4, 5, 7, 8, 12, 17, 18, 19, 20, 26, 28, 34, 38, 39, 40, 41, 42 - B version, 1, 2, 3, 4, 5, 7, 8, 12, 17, 18, 19, 20, 25, 26, 28, 30, 34, 38, 39, 40, 41, 42, 66, 71 - C version
Speed
Zenfone 4 Pro ZS551KL
HSPA 42.2/5.76 Mbps, LTE (3CA) Cat12 600/150 or 100 Mbps
Zenfone 9
HSPA 42.2/5.76 Mbps, LTE (5CA) Cat20 2000/211 Mbps, 5G 4.5/0.9 Gbps
5G bands
Zenfone 4 Pro ZS551KL
-
Zenfone 9
1, 2, 3, 5, 7, 8, 12, 20, 28, 38, 77, 78 - A version, 1, 2, 3, 5, 7, 8, 12, 20, 28, 38, 41, 77, 78 - B version, 1, 2, 3, 5, 7, 8, 12, 20, 25, 28, 38, 40, 41, 66, 71, 77, 78 - C version
Announced
Zenfone 4 Pro ZS551KL
2017, August. Released 2017, October
Zenfone 9
2022, July 28
Status
Zenfone 4 Pro ZS551KL
Discontinued
Zenfone 9
Available. Released 2022, September 15
Dimensions
Zenfone 4 Pro ZS551KL
156.9 x 75.6 x 7.6 mm (6.18 x 2.98 x 0.30 in)
Zenfone 9
146.5 x 68.1 x 9.1 mm (5.77 x 2.68 x 0.36 in)
Weight
Zenfone 4 Pro ZS551KL
175 g (6.17 oz)
Zenfone 9
169 g (5.96 oz)
Build
Zenfone 4 Pro ZS551KL
Glass front (Gorilla Glass 5), glass back (Gorilla Glass 5), aluminum frame
Zenfone 9
Glass front (Gorilla Glass Victus), plastic back, aluminum frame
SIM
Zenfone 4 Pro ZS551KL
Nano-SIM + Nano-SIM
Zenfone 9
Nano-SIM + Nano-SIM
Other
Zenfone 4 Pro ZS551KL
-
Zenfone 9
IP68 dust tight and water resistant (immersible up to 1.5m for 30 min)
Type
Zenfone 4 Pro ZS551KL
AMOLED
Zenfone 9
Super AMOLED, 120Hz, HDR10+, 1100 nits (peak)
Size
Zenfone 4 Pro ZS551KL
5.5 inches, 83.4 cm2 (~70.3% screen-to-body ratio)
Zenfone 9
5.9 inches, 84.4 cm2 (~84.6% screen-to-body ratio)
Resolution
Zenfone 4 Pro ZS551KL
1080 x 1920 pixels, 16:9 ratio (~401 ppi density)
Zenfone 9
1080 x 2400 pixels, 20:9 ratio (~445 ppi density)
Protection
Zenfone 4 Pro ZS551KL
Corning Gorilla Glass 5
Zenfone 9
Corning Gorilla Glass Victus
OS
Zenfone 4 Pro ZS551KL
Android 7.1.1 (Nougat), upgradable to Android 8 (Oreo), ZenUI 4
Zenfone 9
Android 12, upgradable to Android 14
Chipset
Zenfone 4 Pro ZS551KL
Qualcomm MSM8998 Snapdragon 835 (10 nm)
Zenfone 9
Qualcomm SM8475 Snapdragon 8+ Gen 1 (4 nm)
CPU
Zenfone 4 Pro ZS551KL
Octa-core (4x2.45 GHz Kryo & 4x1.9 GHz Kryo)
Zenfone 9
Octa-core (1x3.19 GHz Cortex-X2 & 3x2.75 GHz Cortex-A710 & 4x1.80 GHz Cortex-A510)
GPU
Zenfone 4 Pro ZS551KL
Adreno 540
Zenfone 9
Adreno 730
Card slot
Zenfone 4 Pro ZS551KL
microSDXC (uses shared SIM slot)
Zenfone 9
No
Internal
Zenfone 4 Pro ZS551KL
64GB 6GB RAM, 128GB 6GB RAM
Zenfone 9
128GB 6GB RAM, 128GB 8GB RAM, 256GB 8GB RAM, 256GB 16GB RAM
Other
Zenfone 4 Pro ZS551KL
-
Zenfone 9
UFS 3.1
Dual
Zenfone 4 Pro ZS551KL
12 MP, f/1.7, 25mm (wide), 1/2.55", 1.4µm, dual pixel PDAF, 4-axis OIS 16 MP, 50mm (telephoto), 1/3.1", 1.0µm, AF, 2x optical zoom
Zenfone 9
50 MP, f/1.9, 24mm (wide), 1/1.56", 1.0µm, multi-directional PDAF, gimbal OIS 12 MP, f/2.2, 14mm, 113° (ultrawide), 1/2.55", 1.4µm, dual pixel PDAF
Features
Zenfone 4 Pro ZS551KL
Laser AF, color spectrum sensor, LED flash, HDR, panorama
Zenfone 9
LED flash, HDR, panorama
Video
Zenfone 4 Pro ZS551KL
4K@30fps, 1080p@30/60fps, 1080p@120fps, 720p@240fps
Zenfone 9
8K@24fps, 4K@30/60/120fps, 1080p@30/60/240fps; gyro-EIS, HDR
Single
Zenfone 4 Pro ZS551KL
8 MP, f/1.9, 22mm (wide), 1/3.2", 1.4µm, PDAF
Zenfone 9
12 MP, f/2.5, 28mm (standard), 1/2.93", 1.22µm, dual pixel PDAF
Features
Zenfone 4 Pro ZS551KL
HDR
Zenfone 9
-
Video
Zenfone 4 Pro ZS551KL
1080p@30fps
Zenfone 9
4K@30fps, 1080p@30/60fps
Loudspeaker
Zenfone 4 Pro ZS551KL
Yes, dual speakers
Zenfone 9
Yes, with stereo speakers
3.5mm jack
Zenfone 4 Pro ZS551KL
Yes
Zenfone 9
Yes
Other
Zenfone 4 Pro ZS551KL
24-bit/192kHz audio
Zenfone 9
24-bit/192kHz Hi-Res audio Snapdragon Sound
WLAN
Zenfone 4 Pro ZS551KL
Wi-Fi 802.11 a/b/g/n/ac, dual-band, Wi-Fi Direct
Zenfone 9
Wi-Fi 802.11 a/b/g/n/ac/6e, dual-band, Wi-Fi Direct
Bluetooth
Zenfone 4 Pro ZS551KL
5.0, A2DP, EDR, LE, aptX
Zenfone 9
5.2, A2DP, LE, aptX HD, aptX Adaptive, aptX Lossless
Positioning
Zenfone 4 Pro ZS551KL
GPS, GLONASS, BDS, GALILEO
Zenfone 9
GPS (L1+L5), GLONASS (L1), BDS (B1I+B1c+B2a), GALILEO (E1+E5a), QZSS (L1+L5), NavIC (L5)
NFC
Zenfone 4 Pro ZS551KL
Yes
Zenfone 9
Yes
Infrared port
Zenfone 4 Pro ZS551KL
Yes
Zenfone 9
-
Radio
Zenfone 4 Pro ZS551KL
FM radio
Zenfone 9
No
USB
Zenfone 4 Pro ZS551KL
USB Type-C 2.0, OTG
Zenfone 9
USB Type-C, OTG
Sensors
Zenfone 4 Pro ZS551KL
Fingerprint (front-mounted), accelerometer, gyro, proximity, compass
Zenfone 9
Fingerprint (side-mounted), accelerometer, gyro, proximity, compass
Type
Zenfone 4 Pro ZS551KL
Li-Ion 3600 mAh, non-removable
Zenfone 9
Li-Po 4300 mAh
Charging
Zenfone 4 Pro ZS551KL
18W wired, 50% in 32 min
Zenfone 9
30W wired, PD3.0, PPS, QC4 5W reverse wired
Talk time
Zenfone 4 Pro ZS551KL
Up to 27 h 30 min (3G)
Zenfone 9
-
Colors
Zenfone 4 Pro ZS551KL
Moonlight white, Pure Black
Zenfone 9
Starry Blue, Moonlight White, Sunset Red, Midnight Black
Models
Zenfone 4 Pro ZS551KL
Z01GD, Z01GS
Zenfone 9
AI2202-1A006EU, AI2202, AI2202_B
Price
Zenfone 4 Pro ZS551KL
About 350 EUR
Zenfone 9
£ 895.00 / € 560.12