Asus Zenfone 2 ZE550ML vs ZE551ML: A Detailed Comparison

The Asus Zenfone 2 series was a game-changer in the budget smartphone market, offering impressive specs at an affordable price. But with two popular models, the ZE550ML and ZE551ML, choosing the right one can be tricky. This comprehensive comparison will help you decide which Zenfone 2 best suits your needs.

Phones Images

🏆 Quick Verdict

The ZE551ML is the clear winner, offering a faster processor (especially in the 4GB RAM variant), a slightly improved chipset, and significantly faster charging. While both offer good value, the ZE551ML's performance and charging advantages make it the better choice for most users.

PHONES
Phone Names	Asus Zenfone 2 ZE550ML	Asus Zenfone 2 ZE551ML

Network
2G bands	GSM 850 / 900 / 1800 / 1900 - SIM 1 & SIM 2	GSM 850 / 900 / 1800 / 1900 - SIM 1 & SIM 2
3G bands	HSDPA 850 / 900 / 1900 / 2100	HSDPA 850 / 900 / 1900 / 2100
4G bands	1, 2, 3, 4, 5, 8, 28 - Taiwan	1, 2, 3, 4, 5, 8, 9, 18, 19, 28 - Taiwan
Speed	HSPA 42.2/5.76 Mbps, LTE Cat4 150/50 Mbps	HSPA 42.2/5.76 Mbps, LTE Cat4 150/50 Mbps
Technology	GSM / HSPA / LTE	GSM / HSPA / LTE
	1, 3, 38, 39, 40, 41 - China & India	-

Launch
Announced	2015, March. Released 2015, March	2015, January. Released 2015, March
Status	Discontinued	Discontinued

Body
Build	-	Glass front (Gorilla Glass 3), plastic back, plastic frame
Dimensions	152.5 x 77.2 x 10.9 mm (6.00 x 3.04 x 0.43 in)	152.5 x 77.2 x 10.9 mm (6.00 x 3.04 x 0.43 in)
SIM	Dual SIM (Micro-SIM, dual stand-by)	Dual SIM (Micro-SIM, dual stand-by)
Weight	170 g (6.00 oz)	170 g (6.00 oz)

Display
Protection	Corning Gorilla Glass 3	Corning Gorilla Glass 3
Resolution	720 x 1280 pixels, 16:9 ratio (~267 ppi density)	1080 x 1920 pixels, 16:9 ratio (~401 ppi density)
Size	5.5 inches, 83.4 cm2 (~70.8% screen-to-body ratio)	5.5 inches, 83.4 cm2 (~70.8% screen-to-body ratio)
Type	IPS LCD	IPS LCD

Platform
CPU	Quad-core 1.8 GHz	Quad-core 2.3 GHz (4 GB RAM model)Quad-core 1.8 GHz (2 GB RAM model)
Chipset	Intel Atom Z3560	Intel Atom Z3580 (4 GB RAM model)Intel Atom Z3560 (2 GB RAM model)
GPU	PowerVR G6430	PowerVR G6430
OS	Android 5.0 (Lollipop), upgradable to 6.0 (Marshmallow), ZenUI	Android 5.0 (Lollipop), upgradable to 6.0 (Marshmallow)

Memory
Card slot	microSDXC (dedicated slot)	microSDXC (dedicated slot)
Internal	16GB 2GB RAM	16GB 2GB RAM, 32GB 2GB RAM, 32GB 4GB RAM, 64GB 4GB RAM, 128GB 4GB RAM

Main Camera
Features	Dual-LED dual-tone flash, panorama, HDR	Dual-LED dual-tone flash, panorama, HDR
Single	13 MP, f/2.0, AF	13 MP, f/2.0, AF
Video	1080p@30fps	1080p@30fps

Selfie camera
Single	5 MP, f/2.0	5 MP, f/2.0

Sound
3.5mm jack	Yes	Yes
35mm jack	Yes	Yes
Loudspeaker	Yes	Yes

Comms
Bluetooth	4.0, A2DP, EDR	4.0, A2DP, EDR
NFC	No	Yes
Positioning	GPS, GLONASS	GPS, GLONASS
Radio	FM radio	FM radio, RDS
USB	microUSB 2.0, OTG	microUSB 2.0, OTG
WLAN	Wi-Fi 802.11 a/b/g/n/ac, Wi-Fi Direct, hotspot	Wi-Fi 802.11 a/b/g/n/ac, Wi-Fi Direct, hotspot

Features
Sensors	Accelerometer, proximity, compass	Accelerometer, gyro, proximity, compass

Battery
Charging	-	18W wired, 60% in 40 min
Type	Li-Po 3000 mAh, non-removable	Li-Po 3000 mAh, non-removable

Misc
Colors	Osmium Black, Glamor Red, Ceramic White	Osmium Black, Sheer Gold, Glacier Gray, Glamor Red, Ceramic White
Models	Z008D, Z008	Z00AD, Z00A
Price	About 250 EUR	About 300 EUR
SAR EU	0.35 W/kg (head)	0.35 W/kg (head)

Tests
Battery life	-	Endurance rating 59h
Camera	-	Photo / Video
Loudspeaker	-	Voice 62dB / Noise 61dB / Ring 67dB
Performance	-	Basemark OS II 2.0: 1090Basemark X: 12565

OUR TESTS
Battery (old)	-	Endurance rating 59h
Camera	-	Photo / Video
Loudspeaker	-	Voice 62dB / Noise 61dB / Ring 67dB
Performance	-	Basemark OS II 2.0: 1090Basemark X: 12565

Asus Zenfone 2 ZE550ML

Affordable
Decent display
Good battery life (advertised)

Slower performance
Standard charging
Older chipset

Asus Zenfone 2 ZE551ML

Faster performance (especially 4GB RAM model)
Fast charging (18W)
Improved chipset (Z3580 in 4GB model)
Slightly better potential camera quality

Slightly more expensive
Battery life may vary in real-world usage

Display Comparison

Both models feature a 5.5-inch IPS LCD display with a resolution of 1920x1080 pixels. While the panels are similar, the ZE551ML might have slightly better color accuracy and brightness due to potential manufacturing refinements, though this is difficult to definitively confirm without testing.

Camera Comparison

Both phones feature a 13MP rear camera and a 5MP front camera. Image quality is generally comparable, but the ZE551ML's potentially improved image processing algorithms (due to the newer chipset) might result in slightly better low-light performance and more vibrant colors. Video recording capabilities are similar on both devices.

Performance

The ZE551ML boasts a significant performance advantage, particularly the 4GB RAM variant with the Z3580 chipset and 2.3 GHz CPU. The ZE550ML's 1.8 GHz Atom Z3560 CPU and potentially 2GB of RAM will feel noticeably slower, especially when multitasking or running demanding apps. The ZE551ML's faster processor and more RAM result in smoother navigation and app loading times.

Battery Life

Both models are advertised with a 3000mAh battery and an endurance rating of 59 hours. However, the ZE551ML's 18W fast charging capability (60% in 40 minutes) is a major advantage over the ZE550ML's standard charging, significantly reducing charging times.

Buying Guide

The Asus Zenfone 2 ZE550ML is a good option for users on a very tight budget who prioritize basic functionality and don't need the absolute best performance. The ZE551ML is ideal for those who want a smoother experience, faster charging, and a bit more power for multitasking and gaming, justifying the slightly higher price.