Screen size
Zenfone 4 Pro ZS551KL5.5"
Zenfone 8 FlipWinner: 6.7"+18%
Quick verdict
Zenfone 8 Flip leads the measured specs 14-5.
Measured wins
Zenfone 4 Pro ZS551KL
5
spec wins
Ties
3
equal specs
Zenfone 8 Flip
14
spec wins
Overall winner
Screen size
Technology
Zenfone 4 Pro ZS551KL
GSM / HSPA / LTE
Zenfone 8 Flip
GSM / HSPA / LTE / 5G
2G bands
Zenfone 4 Pro ZS551KL
GSM 850 / 900 / 1800 / 1900 - SIM 1 & SIM 2
Zenfone 8 Flip
GSM 850 / 900 / 1800 / 1900
3G bands
Zenfone 4 Pro ZS551KL
HSDPA 800 / 850 / 900 / 1700(AWS) / 1800 / 1900 / 2100
Zenfone 8 Flip
HSDPA 800 / 850 / 900 / 1700(AWS) / 1900 / 2100
4G bands
Zenfone 4 Pro ZS551KL
Resolution
Refresh rate
Peak brightness
Pixel density
CPU speed
RAM
Storage
Main camera
Front camera
Battery
Wired charging
Weight
Thickness
IP rating
Wi‑Fi
Bluetooth
USB
equal specs5G support
NFC
equal specs3.5mm jack
SD card
equal specsStereo 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 8 Flip
1, 2, 3, 4, 5, 7, 8, 12, 17, 18, 19, 20, 26, 28, 34, 38, 39, 40, 41, 42
Speed
Zenfone 4 Pro ZS551KL
HSPA 42.2/5.76 Mbps, LTE (3CA) Cat12 600/150 or 100 Mbps
Zenfone 8 Flip
HSPA 42.2/5.76 Mbps, LTE (6CA) Cat20 2000/150 Mbps, 5G
5G bands
Zenfone 4 Pro ZS551KL
-
Zenfone 8 Flip
1, 2, 3, 5, 7, 8, 12, 20, 28, 38, 77, 78, 77, 78 SA/NSA
Announced
Zenfone 4 Pro ZS551KL
2017, August. Released 2017, October
Zenfone 8 Flip
2021, May 12
Status
Zenfone 4 Pro ZS551KL
Discontinued
Zenfone 8 Flip
Available. Released 2021, May 13
Dimensions
Zenfone 4 Pro ZS551KL
156.9 x 75.6 x 7.6 mm (6.18 x 2.98 x 0.30 in)
Zenfone 8 Flip
165 x 77.3 x 9.6 mm (6.50 x 3.04 x 0.38 in)
Weight
Zenfone 4 Pro ZS551KL
175 g (6.17 oz)
Zenfone 8 Flip
230 g (8.11 oz)
Build
Zenfone 4 Pro ZS551KL
Glass front (Gorilla Glass 5), glass back (Gorilla Glass 5), aluminum frame
Zenfone 8 Flip
Glass front (Gorilla Glass 6), glass back (Gorilla Glass 3), aluminum frame
SIM
Zenfone 4 Pro ZS551KL
Nano-SIM + Nano-SIM
Zenfone 8 Flip
Nano-SIM + Nano-SIM
Type
Zenfone 4 Pro ZS551KL
AMOLED
Zenfone 8 Flip
Super AMOLED, 90Hz, HDR10+, 700 nits (HBM), 1000 nits (peak)
Size
Zenfone 4 Pro ZS551KL
5.5 inches, 83.4 cm2 (~70.3% screen-to-body ratio)
Zenfone 8 Flip
6.67 inches, 107.4 cm2 (~84.2% screen-to-body ratio)
Resolution
Zenfone 4 Pro ZS551KL
1080 x 1920 pixels, 16:9 ratio (~401 ppi density)
Zenfone 8 Flip
1080 x 2400 pixels, 20:9 ratio (~395 ppi density)
Protection
Zenfone 4 Pro ZS551KL
Corning Gorilla Glass 5
Zenfone 8 Flip
Corning Gorilla Glass 6
OS
Zenfone 4 Pro ZS551KL
Android 7.1.1 (Nougat), upgradable to Android 8 (Oreo), ZenUI 4
Zenfone 8 Flip
Android 11, upgradable to Android 13
Chipset
Zenfone 4 Pro ZS551KL
Qualcomm MSM8998 Snapdragon 835 (10 nm)
Zenfone 8 Flip
Qualcomm SM8350 Snapdragon 888 5G (5 nm)
CPU
Zenfone 4 Pro ZS551KL
Octa-core (4x2.45 GHz Kryo & 4x1.9 GHz Kryo)
Zenfone 8 Flip
Octa-core (1x2.84 GHz Cortex-X1 & 3x2.42 GHz Cortex-A78 & 4x1.80 GHz Cortex-A55)
GPU
Zenfone 4 Pro ZS551KL
Adreno 540
Zenfone 8 Flip
Adreno 660
Card slot
Zenfone 4 Pro ZS551KL
microSDXC (uses shared SIM slot)
Zenfone 8 Flip
microSDXC (dedicated slot)
Internal
Zenfone 4 Pro ZS551KL
64GB 6GB RAM, 128GB 6GB RAM
Zenfone 8 Flip
128GB 8GB RAM, 256GB 8GB RAM
Other
Zenfone 4 Pro ZS551KL
-
Zenfone 8 Flip
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 8 Flip
-
Features
Zenfone 4 Pro ZS551KL
Laser AF, color spectrum sensor, LED flash, HDR, panorama
Zenfone 8 Flip
Dual-LED flash, HDR, auto panorama (motorized rotation)
Video
Zenfone 4 Pro ZS551KL
4K@30fps, 1080p@30/60fps, 1080p@120fps, 720p@240fps
Zenfone 8 Flip
8K@30fps, 4K@30/60/120fps, 1080p@30/60/240fps, 720p@480fps; gyro-EIS, HDR
Triple
Zenfone 4 Pro ZS551KL
-
Zenfone 8 Flip
64 MP, f/1.8, 26mm (wide), 1/1.73", 0.8µm, PDAF 8 MP, f/2.4, 80mm (telephoto), PDAF, 3x optical zoom 12 MP, f/2.2, 112˚, 14mm (ultrawide), 1/2.55", 1.4µm, dual pixel PDAF
Single
Zenfone 4 Pro ZS551KL
8 MP, f/1.9, 22mm (wide), 1/3.2", 1.4µm, PDAF
Zenfone 8 Flip
-
Features
Zenfone 4 Pro ZS551KL
HDR
Zenfone 8 Flip
Dual-LED flash, HDR, auto panorama (motorized rotation)
Video
Zenfone 4 Pro ZS551KL
1080p@30fps
Zenfone 8 Flip
8K@30fps, 4K@30/60/120fps, 1080p@30/60/240fps, 720p@480fps; gyro-EIS, HDR
Triple
Zenfone 4 Pro ZS551KL
-
Zenfone 8 Flip
Motorized flip-up main camera module
Loudspeaker
Zenfone 4 Pro ZS551KL
Yes, dual speakers
Zenfone 8 Flip
Yes, with stereo speakers
3.5mm jack
Zenfone 4 Pro ZS551KL
Yes
Zenfone 8 Flip
No
Other
Zenfone 4 Pro ZS551KL
24-bit/192kHz audio
Zenfone 8 Flip
24-bit/192kHz Hi-Res audio
WLAN
Zenfone 4 Pro ZS551KL
Wi-Fi 802.11 a/b/g/n/ac, dual-band, Wi-Fi Direct
Zenfone 8 Flip
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 8 Flip
5.2, A2DP, LE, aptX HD, aptX Adaptive
Positioning
Zenfone 4 Pro ZS551KL
GPS, GLONASS, BDS, GALILEO
Zenfone 8 Flip
GPS (L1+L5), GLONASS (L1), BDS (B1I+B1c+B2a), GALILEO (E1+E5a), QZSS (L1+L5), NavIC (L5)
NFC
Zenfone 4 Pro ZS551KL
Yes
Zenfone 8 Flip
Yes
Infrared port
Zenfone 4 Pro ZS551KL
Yes
Zenfone 8 Flip
-
Radio
Zenfone 4 Pro ZS551KL
FM radio
Zenfone 8 Flip
No
USB
Zenfone 4 Pro ZS551KL
USB Type-C 2.0, OTG
Zenfone 8 Flip
USB Type-C 2.0
Sensors
Zenfone 4 Pro ZS551KL
Fingerprint (front-mounted), accelerometer, gyro, proximity, compass
Zenfone 8 Flip
Fingerprint (under display, optical), accelerometer, gyro, proximity, compass
Type
Zenfone 4 Pro ZS551KL
Li-Ion 3600 mAh, non-removable
Zenfone 8 Flip
Li-Po 5000 mAh
Charging
Zenfone 4 Pro ZS551KL
18W wired, 50% in 32 min
Zenfone 8 Flip
30W wired, PD3.0
Talk time
Zenfone 4 Pro ZS551KL
Up to 27 h 30 min (3G)
Zenfone 8 Flip
-
Colors
Zenfone 4 Pro ZS551KL
Moonlight white, Pure Black
Zenfone 8 Flip
Galactic Black, Glacier Silver
Models
Zenfone 4 Pro ZS551KL
Z01GD, Z01GS
Zenfone 8 Flip
ZS672KS, I004D
Price
Zenfone 4 Pro ZS551KL
About 350 EUR
Zenfone 8 Flip
About 380 EUR