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Asus ZenFone 3 ZE552KL Smartphone Review

Designer piece. Asus has treated the 5.5-inch ZenFone 3 to premium looks while keeping performance and configuration in mind. The outcome is a good and affordable mid-range smartphone that hardly exhibits any shortcomings in the test.

For the original German review, see here.

With the ZenFone 3 ZE552KL, Asus sends a mid-range smartphone into the race, which is supposed to convince primarily with its two (8 and 16 megapixel) camera modules. However, that alone is not enough to outclass the opponents in the hard-fought market sector of up to around 400 Euros (~$440). Therefore, Asus has provided the 5.5-inch ZenFone 3, officially priced at 359 Euros (~$395), other virtues, as well. With a Qualcomm Snapdragon 625 octa-core SoC, integrated Qualcomm Adreno 506 graphics chip, and generous 4 GB of RAM, the ZE552KL is based on a very solid platform that fits well into the smartphone's mid-range positioning. The other configuration specs are also impressive: 64 GB of storage, a 2.5D Corning Gorilla glass-protected IPS panel with a resolution of 1920x1080 pixels, the latest Android 6.0, and a wireless module with Wi-Fi 802.11ac and LTE.

Asus offers other configurations besides the ZE552KL. Starting with the almost technically identical but marginally smaller 5.2-inch ZenFone 3 ZE520KL. It is based on the same SoC, but only sports 3 GB of RAM. The battery capacity is also a bit lower (2650 mAh vs. 3000 mAh). The other two members of the ZenFone 3 family make use of the superlative: The 5.7-inch ZenFone 3 Deluxe configuration of 6 GB of RAM and 256 GB of storage makes it the premium model of the lineup and is allegedly on par with high-end handsets such as Samsung's Galaxy S7. If a smartphone cannot be big enough, the ZenFone 3 Ultra is a genuine phablet with a 6.8-inch screen.

Back to the ZE552KL: We let our review sample compete against the identically configured Honor 8, OnePlus 3, Samsung Galaxy A5 (2016), and ZTE Axon 7.

Asus Zenfone 3 ZE552KL (Zenfone Series)
Processor
Qualcomm Snapdragon 625 8 x 2 GHz, Cortex-A53
Graphics adapter
Qualcomm Adreno 506, Core: 650 MHz
Memory
4 GB 
, LPDDR3
Display
5.50 inch 16:9, 1920 x 1080 pixel 401 PPI, 10 finger-touchscreen, glove mode, IPS, Bluelight filter, glossy: yes
Storage
64 GB eMMC Flash, 64 GB 
, 51.7 GB free
Connections
1 USB 2.0, 1 Infrared, Audio Connections: 3.5 mm headset jack, Card Reader: micro-SD max. 2 TB, 1 Fingerprint Reader, Brightness Sensor, Sensors: accelerometer, gyroscope, proximity sensor, compass, Wi-Fi Direct, USB-OTG, DLNA, Miracast, Qualcomm Quick Charge 3.0
Networking
802.11 a/b/g/n/ac (a/b/g/n = Wi-Fi 4/ac = Wi-Fi 5/), Bluetooth 4.2, GSM (850, 900, 1800, 1900 MHz), UMTS (850, ​900, ​1900, ​2100 MHz), LTE Cat. 4 (800, 850, 900, 1800, 1900, 2100, 2600 MHz), max. download 150 MBit/s, max. upload 50 MBit/s, SAR: 0.493 W/kg, Dual SIM, LTE, GPS
Size
height x width x depth (in mm): 7.7 x 152.6 x 77.4 ( = 0.3 x 6.01 x 3.05 in)
Battery
3000 mAh Lithium-Ion
Operating System
Android 6.0 Marshmallow
Camera
Primary Camera: 16 MPix f/2.0, dual-LED flash, autofocus, HDR, optical image stabilizer, 4K video recordings (3840 x 2160 Pixel)/1080p/720p at 30 FPS
Secondary Camera: 8 MPix f/2.0, max. video recordings 1080p at 30 fps
Additional features
Speakers: mono, Keyboard: virtual, Keyboard Light: yes, USB Type-C cable, modular power supply, in-ear headphone, quick start guide, Asus ZenUI 3.0, 24 Months Warranty, USB Type-C, fanless
Weight
155 g ( = 5.47 oz / 0.34 pounds), Power Supply: 35 g ( = 1.23 oz / 0.08 pounds)
Price
359 Euro
Note: The manufacturer may use components from different suppliers including display panels, drives or memory sticks with similar specifications.

 

Case

The slim 7.7-millimeter (~0.3 in) casing of Asus' ZenFone 3 is completely made of metal that is glass protected on both the front and rear. The sleek surfaces display some more fingerprints than smartphones with a matte or rubber-coated back cover would. However, this is not a drawback in terms of feel. The smartphone could be held safely in the test, and it never conveyed the feeling that it would slip out of our hands. Furthermore, the material composition of glass and metal give the ZE552KL high stability - even stronger warping attempts did not affect the smartphone. Nevertheless, the ZenFone 3 is not invulnerable as we accidentally found out: The smartphone sustained some minor injuries after falling from a table. These were, however, limited to superficial scratches on the display's lower right edge (see third screenshot in the gallery).

In total, the ZE552KL looks very high quality. The 2.5D Corning Gorilla glass-protected IPS panel contributes to this to some degree. The screen surface is lightly curved at the corners and edges, and it is inserted seamlessly into the slightly lower surrounding metal bezel. A fingerprint scanner is situated on the rear below the primary camera. It not only allows unlocking the smartphone, but also launches the camera, allows taking photos, and accepting incoming calls.

Asus offers the ZenFone in four different colors: Moonlight White, Shimmer Gold, Aqua Blue and Sapphire Black. The latter adorns our review sample.

Size Comparison

152.6 mm / 6.01 in 77.4 mm / 3.05 in 7.7 mm / 0.3031 in 155 g0.3417 lbs152.7 mm / 6.01 in 74.7 mm / 2.94 in 7.35 mm / 0.2894 in 161 g0.3549 lbs145.5 mm / 5.73 in 71 mm / 2.8 in 7.45 mm / 0.2933 in 153 g0.3373 lbs144.8 mm / 5.7 in 71 mm / 2.8 in 7.3 mm / 0.2874 in 155 g0.3417 lbs148 mm / 5.83 in 105 mm / 4.13 in 1 mm / 0.03937 in 1.5 g0.00331 lbs

Connectivity

Qualcomm's Snapdragon 625 octa-core processor clocks inside Asus' ZenFone 3. It can fall back on 4 GB of LPDDR3 RAM. Technically, the CPU, as well as the integrated Adreno 506 graphics chip, is situated in the mid-range. Applications should thus run just as smoothly as graphically demanding games.

Almost 52 GB of the 64 GB storage in the ZE552KL are available out of the box. The internal storage can be expanded via a micro-SD card when the dual-SIM feature is not used. A maximum of 2 TB is possible. The micro-SD could only be formatted as portable storage and not internal storage in the test. Moving apps to the micro-SD card (App2SD) was thus not possible. In return, the ZE552KL supports DLNA that Asus calls "Digital Media Server", and Miracast ("PlayTo"). Both are found in the settings in the menu item "more". Asus' handset does not support NFC.

A USB 2.0 port is situated on the smartphone's lower edge. It can be used for connecting peripherals via USB OTG. Furthermore, the USB port is implemented as Type-C, which allows connecting plugs with either side since both sides are the same. The USB Type-C port also provides the basis for another convenient feature: The Quick Charge 3.0 technology by Qualcomm. It takes advantage of the higher voltages and electric currents that USB Type-C can provide in contrast to a standard USB port. The deactivated smartphone only needed a bit less than two hours to recharge fully.

Left: Dual-SIM/micro-SD slot
Left: Dual-SIM/micro-SD slot
Right: Power button, volume control
Right: Power button, volume control
Upper edge: Headset jack
Upper edge: Headset jack
Lower edge: Type-C USB port
Lower edge: Type-C USB port

Software

Asus ships the ZenFone 3 with Android 6.0.1 Marshmallow. Rather than the stock user interface, Asus installs its self-developed ZenUI 3.0. ZenUI does not change the fundamental handling compared with the proprietary GUI. However, it involves a slightly different design and interesting additional features. Furthermore, the latest iteration of ZenUI is also a bit more colorful than the former ZenUI 2.0.

For example, animated backgrounds and the app "Game Genie" that allows streaming games via YouTube and Twitch are new. "Mobile Asus Manager" is also preloaded. This is a kind of tuning app that, for example, frees storage, regulates power consumption, and scans the smartphone for security risks. The tool collection also includes known applications, such as the "Laser Ruler". This app uses the ZenFone 3's laser autofocus to measure the distance between the smartphone and a determined object. However, this only functions over short distances of up to 1.5 meters (~4.9 feet).

Besides many practical apps, Asus has also preloaded a number of niche apps, like TripAdvisor, Puffin or MiniMovie, on the smartphone. Less would have been more here since these apps cannot be uninstalled, but at most disabled and thus unnecessarily reserve storage capacity.

Communication and GPS

Asus' ZenFone 3 supports the 802.11 a/b/g/n/ac Wi-Fi standards in the 2.4 and 5 GHz networks. Although data sharing via our Linksys EA8500 was very stable, it was also disappointingly slow. The smartphone barely surpassed 30 MBit/s. Rivals, such as OnePlus' 3 and ZTE's Axon 7, are pretty much exactly ten times faster in Wi-Fi.

Our ZenFone 3 review sample is the international version supporting up to LTE Cat. 4 (150 MBit/s max. down; max. 50 MBit/s up). According to the specifications, the same smartphone for the Chinese market supports speeds of up to LTE Cat. 7 (300 MBit/s down; 100 Mbit up) while certain Asian territories like Taiwan, Japan, Hong Kong, Philippines, and Singapore support Cat. 6 (300 MBit/s down; 50 MBit/s up).

Networking
iperf3 transmit AX12
OnePlus 3
Adreno 530, 820 MSM8996, 64 GB UFS 2.0 Flash
323 MBit/s +935%
ZTE Axon 7
Adreno 530, 820 MSM8996, 64 GB eMMC Flash
298 MBit/s +855%
Asus Zenfone 3 ZE552KL
Adreno 506, 625, 64 GB eMMC Flash
31.2 MBit/s
iperf3 receive AX12
ZTE Axon 7
Adreno 530, 820 MSM8996, 64 GB eMMC Flash
337 MBit/s +924%
OnePlus 3
Adreno 530, 820 MSM8996, 64 GB UFS 2.0 Flash
320 MBit/s +873%
Asus Zenfone 3 ZE552KL
Adreno 506, 625, 64 GB eMMC Flash
32.9 MBit/s
GPS: Outdoors
GPS: Outdoors
GPS: Indoors
GPS: Indoors

The ZenFone 3 can utilize GPS, A-GPS, GLONASS, and BDSS for localization. In the test, the smartphone found our position quickly and with high accuracy no matter if we were indoors or out.

We tested how well the ZenFone 3 fares in practice on our approximately 12-kilometer bike test route alongside Garmin's Edge 500 professional GPS for comparison. The ZE552KL did a good job although it sometimes placed us slightly off-route. In the end, the smartphone and professional navigation system only deviated by approximately 200 meters (~220 yards) on the total route. This is negligible in view of the distance. Thus, the ZenFone 3's GPS is sufficient for everyday app use.

Asus Zenfone 3: Total route
Asus Zenfone 3: Total route
Asus Zenfone 3: Turning point
Asus Zenfone 3: Turning point
Asus Zenfone 3: Bridge
Asus Zenfone 3: Bridge
Garmin Edge 500: Total route
Garmin Edge 500: Total route
Garmin Edge 500: Turning point
Garmin Edge 500: Turning point
Garmin Edge 500: Bridge
Garmin Edge 500: Bridge

Telephone and Call Quality

Phone app: Smart Dial
Phone app: Smart Dial
Phone app: Keypad
Phone app: Keypad

Big surprises are not expected from a phone app: Contact list, keypad, and call lists - Asus' ZenFone 3 also provides this. When using two SIM cards, one can be preferred for telephony or be set up for call forwarding in case the other card is not available.

The ZenFone 3 made a good impression in calls. The voice quality was impeccable during the test regardless whether the contact used the landline or a mobile network connection. Interfering background noises were not an issue during the calls. The speaker's position in the ZenFone 3 proved advantageous in hands-free mode. The contact is clear even when the ZenFone 3 is placed on a table since the small sound membranes are situated on the smartphone's lower edge.

Cameras

Primary camera photo (click for original)
Primary camera photo (click for original)
Webcam photo (click for original)
Webcam photo (click for original)

The ZenFone 3 has an 8-megapixel webcam with an f/2.0 aperture, which promises decent light sensitivity. In fact, the webcam produces satisfactory pictures at up to 3264x2448 pixels, which can also be prettied up via additional photo modes, such as beautify (especially for selfies), HDR or GIF animations. The webcam records videos at up to 1920x1080 pixels and 30 frames per second.

The 16-megapixel primary camera also relies on an f/2.0 aperture. The camera lens is Sony's IMX298 with six camera lenses and optical image stabilizer. The focus system is a triple mechanism called "TriTech", in which a contrast-based autofocus works together with a laser autofocus and phase detection autofocus. According to the spec sheet, it focuses within 30 milliseconds - it functioned impeccably in testing routine. Other features are a dual-LED flash, a selectable HDR function and the option of setting important photography parameters like sensitivity, white balance, and exposure time manually.

Photos in the native resolution (4656x3492 pixels) are only possible in the 4:3 format. The resolution has to be reduced to 12 megapixels for 16:9 photos. The video quality can be increased up to 4K (3840x2160 pixels).

At first glance, the 16-megapixel camera delivers good photos with vivid colors. The photos are not bad even when looking closer. However, fine image details are only displayed more or less faded up to frayed in every single test photo. ZTE's Axon 7 and OnePlus' 3 do a much better job here, and they both add a bit more dynamics. Then again, Asus' handset fares well in night shots although image noise becomes apparent fairly quickly.

Image Comparison

Choose a scene and navigate within the first image. One click changes the position on touchscreens. One click on the zoomed-in image opens the original in a new window. The first image shows the scaled photograph of the test device.

Scene 1Scene 2Scene 3
orginal image
click to load images

Besides our test photos, we check the sharpness and colors in defined test conditions. For this, we photograph ColorChecker Passport and our test chart as full-frame as possible. The photos are not edited afterward. The ZenFone 3 reproduced colors are a bit too warm and saturated - although this does not really look natural, the photos look good with it. Users can set the color temperature manually if the reproduction does not appeal to them. The ZenFone 3's definition is satisfactory although the transitions between the single photo elements are always slightly frayed.

Screenshot of ColorChecker colors. Original colors are displayed in the lower half of each patch.
Screenshot of ColorChecker colors. Original colors are displayed in the lower half of each patch.
Test photo section
Test photo section
Test photo (click for original)
Test photo (click for original)

Accessories and Warranty

Asus ships the ZenFone 3 with a modular power supply, USB Type-C cable, an in-ear headset, a quick start guide, and warranty card. The manufacturer does not offer any product-specific accessories for its smartphone on its website. The ZenFone 3 comes with a 24-month warranty. The battery and included accessories are only covered for 6 months. Please see our Guarantees, Return Policies & Warranties FAQ for country-specific information.

Input Devices and Handling

The capacitive touchscreen in Asus' ZenFone 3 offers the fingers little resistance and can process up to 10 inputs simultaneously. The Full HD panel implements commands very quickly and accurately up into the corners. This even worked when wearing gloves. The ZenUI interface can then be used just as smoothly. Stutters or other interruptions of any kind were not noticed during the test.

The virtual keyboard's diverse input options are praiseworthy. It fades in a number bar and facilitates handling via swipe inputting and word suggestions by default. The keyboard can be scaled up by up to two-thirds of the screen optionally, but not much of the screen content remains then. The Android buttons are implemented as sensor keys below the screen, but they are unfortunately not backlit.

One screen setting that could contribute to more comfortable operation is the blue light filter that can be activated via screen and quick settings. It reduces blue light to prevent eyestrain.

Keyboard portrait mode
Keyboard portrait mode
Keyboard landscape mode
Keyboard landscape mode

Display

Subpixels
Subpixels

The IPS panel in Asus' ZenFone 3 has a resolution of 1920x1080 pixels and achieves a high pixel density of 401 PPI, which results in a razor-sharp reproduction. Furthermore, a very homogeneous illumination of 93 percent and high brightness, on average 633.2 cd/m², very clearly outperforms the competition. OnePlus' 3 and Honor's 8 are the first to follow at quite some long distance with 431 cd/m² and 443 cd/m². The ZenFone 3 can automatically adapt the screen brightness via its ambient light sensor so that it does not get too bright. For a change, the ZE552KL does not present a top rate in black level with 0.66 cd/m², but its high contrast of 997:1 compensate this.

Users can choose among the four display color modes "Balance", "Blue light filter", "Vivid", and "Adapted". The relatively color-neutral "Balance" mode is set by default while switching to "Vivid" visibly brightens up the reproduction.

635
cd/m²
634
cd/m²
651
cd/m²
630
cd/m²
658
cd/m²
636
cd/m²
625
cd/m²
610
cd/m²
620
cd/m²
Distribution of brightness
tested with X-Rite i1Pro 2
Maximum: 658 cd/m² (Nits) Average: 633.2 cd/m² Minimum: 5.22 cd/m²
Brightness Distribution: 93 %
Center on Battery: 658 cd/m²
Contrast: 997:1 (Black: 0.66 cd/m²)
ΔE Color 4.9 | 0.5-29.43 Ø4.92
ΔE Greyscale 5.8 | 0.5-98 Ø5.2
Gamma: 2.26
Asus Zenfone 3 ZE552KL
IPS, 1920x1080, 5.5"
OnePlus 3
Optic-AMOLED, 1920x1080, 5.5"
Samsung Galaxy A5 2016
Super AMOLED, 1920x1080, 5.2"
Honor 8
IPS, 1920x1080, 5.2"
ZTE Axon 7
AMOLED, 2560x1440, 5.5"
Screen
-9%
18%
-6%
-18%
Brightness middle
658
419
-36%
378
-43%
451
-31%
328
-50%
Brightness
633
431
-32%
380
-40%
443
-30%
334
-47%
Brightness Distribution
93
84
-10%
91
-2%
93
0%
88
-5%
Black Level *
0.66
0.4
39%
Contrast
997
1128
13%
Colorchecker dE 2000 *
4.9
4.1
16%
1.95
60%
5.4
-10%
4.6
6%
Colorchecker dE 2000 max. *
9.1
12
-32%
3.09
66%
9.9
-9%
14.7
-62%
Greyscale dE 2000 *
5.8
3.3
43%
1.86
68%
6.7
-16%
2.8
52%
Gamma
2.26 97%
2.1 105%
2.13 103%
2.33 94%
2.29 96%
CCT
7840 83%
6550 99%
6376 102%
8262 79%
6612 98%
Color Space (Percent of AdobeRGB 1998)
89.38
Color Space (Percent of sRGB)
100

* ... smaller is better

Examining the ZenFone 3's subjectively impeccable reproduction in an objective test using a spectrophotometer and professional CalMAN software exhibits some weaknesses after all. The shifts in the color and grayscale reproduction are both higher than ideal (DeltaE <3) in the preset "Balance" mode. The color temperature of 7840 K also clearly overshoots the target (6500 K), which lets the image look slightly too cool. Then, all aberrations are even a bit higher in "Vivid" mode. However, the measured inaccuracies are virtually not noticed in everyday use, especially since the color reproduction can be set at will.

ColorChecker (target color space: sRGB; color profile: "Balance")
ColorChecker (target color space: sRGB; color profile: "Balance")
Colorspace (target color space: sRGB; color profile: "Balance")
Colorspace (target color space: sRGB; color profile: "Balance")
Grayscale (target color space: sRGB; color profile: "Balance")
Grayscale (target color space: sRGB; color profile: "Balance")
Saturation Sweeps (target color space: sRGB; color profile: "Balance")
Saturation Sweeps (target color space: sRGB; color profile: "Balance")
ColorChecker (target color space: sRGB; color profile: "Vivid")
ColorChecker (target color space: sRGB; color profile: "Vivid")
Colorspace (target color space: sRGB; color profile: "Vivid")
Colorspace (target color space: sRGB; color profile: "Vivid")
Grayscale (target color space: sRGB; color profile: "Vivid")
Grayscale (target color space: sRGB; color profile: "Vivid")
Saturation Sweeps (target color space: sRGB; color profile: "Vivid")
Saturation Sweeps (target color space: sRGB; color profile: "Vivid")

Display Response Times

Display response times show how fast the screen is able to change from one color to the next. Slow response times can lead to afterimages and can cause moving objects to appear blurry (ghosting). Gamers of fast-paced 3D titles should pay special attention to fast response times.
       Response Time Black to White
36 ms ... rise ↗ and fall ↘ combined↗ 15 ms rise
↘ 21 ms fall
The screen shows slow response rates in our tests and will be unsatisfactory for gamers.
In comparison, all tested devices range from 0.1 (minimum) to 240 (maximum) ms. » 93 % of all devices are better.
This means that the measured response time is worse than the average of all tested devices (21 ms).
       Response Time 50% Grey to 80% Grey
56 ms ... rise ↗ and fall ↘ combined↗ 17 ms rise
↘ 39 ms fall
The screen shows slow response rates in our tests and will be unsatisfactory for gamers.
In comparison, all tested devices range from 0.165 (minimum) to 636 (maximum) ms. » 92 % of all devices are better.
This means that the measured response time is worse than the average of all tested devices (32.9 ms).

Screen Flickering / PWM (Pulse-Width Modulation)

To dim the screen, some notebooks will simply cycle the backlight on and off in rapid succession - a method called Pulse Width Modulation (PWM) . This cycling frequency should ideally be undetectable to the human eye. If said frequency is too low, users with sensitive eyes may experience strain or headaches or even notice the flickering altogether.
Screen flickering / PWM not detected

In comparison: 53 % of all tested devices do not use PWM to dim the display. If PWM was detected, an average of 8747 (minimum: 5 - maximum: 343500) Hz was measured.

Thanks to the screen's high brightness, the viewing angle stable Asus ZenFone 3 is very suitable for outdoor use. Of course, the reflective glass surface is distracting in unfavorable light conditions, but it ultimately does not affect use decisively. The ZenFone 3 also reaps in good ratings in viewing angle stability thanks to its IPS panel. The screen only looks a bit brighter or darker in extreme viewing perspectives, but this does not have an impact on legibility.

Viewing angles
Viewing angles
Outdoors
Outdoors

Performance

Powered by Qualcomm's mid-range Snapdragon 625 and 4 GB of RAM, Asus' ZenFone 3 achieves a decent performance that always ensured a smooth workflow in the test. The benchmarks illustrate the smartphone's real potentials. The ZenFone 3 places itself just before Samsung's Galaxy A5 (2016) but cannot catch up to the overall slightly faster Honor's 8 and OnePlus' 3 in the synthetic tests.

AnTuTu v6 - Total Score (sort by value)
Asus Zenfone 3 ZE552KL
62484 Points
ZTE Axon 7
122524 Points +96%
Honor 8
94671 Points +52%
Samsung Galaxy A5 2016
41676 Points -33%
OnePlus 3
142090 Points +127%
Geekbench 4.0
64 Bit Multi-Core Score (sort by value)
Asus Zenfone 3 ZE552KL
4042 Points
ZTE Axon 7
3867 Points -4%
Honor 8
5481 Points +36%
OnePlus 3
4097 Points +1%
64 Bit Single-Core Score (sort by value)
Asus Zenfone 3 ZE552KL
820 Points
ZTE Axon 7
1280 Points +56%
Honor 8
1726 Points +110%
OnePlus 3
1754 Points +114%
3DMark
1280x720 offscreen Ice Storm Unlimited Score (sort by value)
Asus Zenfone 3 ZE552KL
13955 Points
ZTE Axon 7
23319 Points +67%
Honor 8
20235 Points +45%
Samsung Galaxy A5 2016
7903 Points -43%
OnePlus 3
30241 Points +117%
1280x720 offscreen Ice Storm Unlimited Graphics Score (sort by value)
Asus Zenfone 3 ZE552KL
13466 Points
ZTE Axon 7
24310 Points +81%
Honor 8
22157 Points +65%
Samsung Galaxy A5 2016
7542 Points -44%
OnePlus 3
34023 Points +153%
1280x720 offscreen Ice Storm Unlimited Physics (sort by value)
Asus Zenfone 3 ZE552KL
15984 Points
ZTE Axon 7
20408 Points +28%
Honor 8
15531 Points -3%
Samsung Galaxy A5 2016
9495 Points -41%
OnePlus 3
21771 Points +36%
2560x1440 Sling Shot OpenGL ES 3.0 (sort by value)
Asus Zenfone 3 ZE552KL
842 Points
ZTE Axon 7
2698 Points +220%
Honor 8
1273 Points +51%
Samsung Galaxy A5 2016
336 Points -60%
OnePlus 3
3424 Points +307%
2560x1440 Sling Shot OpenGL ES 3.0 Graphics (sort by value)
Asus Zenfone 3 ZE552KL
719 Points
ZTE Axon 7
4619 Points +542%
Honor 8
1112 Points +55%
Samsung Galaxy A5 2016
275 Points -62%
OnePlus 3
4633 Points +544%
2560x1440 Sling Shot OpenGL ES 3.0 Physics (sort by value)
Asus Zenfone 3 ZE552KL
2112 Points
ZTE Axon 7
1099 Points -48%
Honor 8
2587 Points +22%
Samsung Galaxy A5 2016
1479 Points -30%
OnePlus 3
1789 Points -15%
GFXBench (DX / GLBenchmark) 2.7
T-Rex Onscreen (sort by value)
Asus Zenfone 3 ZE552KL
21 fps
ZTE Axon 7
53 fps +152%
Honor 8
43 fps +105%
Samsung Galaxy A5 2016
14 fps -33%
OnePlus 3
60 fps +186%
1920x1080 T-Rex Offscreen (sort by value)
Asus Zenfone 3 ZE552KL
23 fps
ZTE Axon 7
88 fps +283%
Honor 8
41 fps +78%
Samsung Galaxy A5 2016
14 fps -39%
OnePlus 3
89 fps +287%
GFXBench 3.0
on screen Manhattan Onscreen OGL (sort by value)
Asus Zenfone 3 ZE552KL
9.7 fps
ZTE Axon 7
28 fps +189%
Honor 8
19 fps +96%
Samsung Galaxy A5 2016
3.8 fps -61%
OnePlus 3
46 fps +374%
1920x1080 1080p Manhattan Offscreen (sort by value)
Asus Zenfone 3 ZE552KL
9.9 fps
ZTE Axon 7
39 fps +294%
Honor 8
19 fps +92%
Samsung Galaxy A5 2016
3.8 fps -62%
OnePlus 3
47 fps +375%
GFXBench 3.1
on screen Manhattan ES 3.1 Onscreen (sort by value)
Asus Zenfone 3 ZE552KL
6.1 fps
ZTE Axon 7
16 fps +162%
Honor 8
11 fps +80%
OnePlus 3
30 fps +392%
1920x1080 Manhattan ES 3.1 Offscreen (sort by value)
Asus Zenfone 3 ZE552KL
6.2 fps
ZTE Axon 7
31 fps +400%
Honor 8
10 fps +61%
OnePlus 3
31 fps +400%
PCMark for Android - Work performance score (sort by value)
Asus Zenfone 3 ZE552KL
6785 Points
ZTE Axon 7
4970 Points -27%
Honor 8
6735 Points -1%
Samsung Galaxy A5 2016
4008 Points -41%
OnePlus 3
7101 Points +5%
BaseMark OS II
Overall (sort by value)
Asus Zenfone 3 ZE552KL
1215 Points
ZTE Axon 7
2165 Points +78%
Honor 8
2034 Points +67%
Samsung Galaxy A5 2016
810 Points -33%
OnePlus 3
2496 Points +105%
System (sort by value)
Asus Zenfone 3 ZE552KL
2923 Points
ZTE Axon 7
3307 Points +13%
Honor 8
3952 Points +35%
Samsung Galaxy A5 2016
2153 Points -26%
OnePlus 3
3537 Points +21%
Memory (sort by value)
Asus Zenfone 3 ZE552KL
1042 Points
ZTE Axon 7
1489 Points +43%
Honor 8
2556 Points +145%
Samsung Galaxy A5 2016
554 Points -47%
OnePlus 3
2052 Points +97%
Graphics (sort by value)
Asus Zenfone 3 ZE552KL
1019 Points
ZTE Axon 7
4631 Points +354%
Honor 8
1703 Points +67%
Samsung Galaxy A5 2016
488 Points -52%
OnePlus 3
4813 Points +372%
Web (sort by value)
Asus Zenfone 3 ZE552KL
702 Points
ZTE Axon 7
963 Points +37%
Honor 8
994 Points +42%
Samsung Galaxy A5 2016
741 Points +6%
OnePlus 3
1112 Points +58%

Legend

 
Asus Zenfone 3 ZE552KL Qualcomm Snapdragon 625, Qualcomm Adreno 506, 64 GB eMMC Flash
 
ZTE Axon 7 Qualcomm Snapdragon 820 MSM8996, Qualcomm Adreno 530, 64 GB eMMC Flash
 
Honor 8 HiSilicon Kirin 950, ARM Mali-T880 MP4, 32 GB eMMC Flash
 
Samsung Galaxy A5 2016 Samsung Exynos 7580 Octa, ARM Mali-T720 MP2, 16 GB eMMC Flash
 
OnePlus 3 Qualcomm Snapdragon 820 MSM8996, Qualcomm Adreno 530, 64 GB UFS 2.0 Flash

The same impression as in the synthetic tests arises in the browser benchmarks. Again, the ZenFone 3 passes the finish line before the Samsung Galaxy A5 (2016). However, Honor 8 and OnePlus 3 are already waiting there.

Octane V2 - Total Score (sort by value)
Asus Zenfone 3 ZE552KL
4905 Points
OnePlus 3
9155 Points +87%
Samsung Galaxy A5 2016
3611 Points -26%
Honor 8
10692 Points +118%
ZTE Axon 7
8062 Points +64%
Mozilla Kraken 1.1 - Total (sort by value)
Asus Zenfone 3 ZE552KL
8041 ms *
OnePlus 3
2921 ms * +64%
Samsung Galaxy A5 2016
11887 ms * -48%
Honor 8
2979 ms * +63%
ZTE Axon 7
3097 ms * +61%
WebXPRT 2015 - Overall (sort by value)
Asus Zenfone 3 ZE552KL
84 Points
OnePlus 3
122 Points +45%
Samsung Galaxy A5 2016
64 Points -24%
Honor 8
138 Points +64%
ZTE Axon 7
111 Points +32%
JetStream 1.1 - Total Score (sort by value)
Asus Zenfone 3 ZE552KL
31.12 Points
OnePlus 3
54.4 Points +75%
Samsung Galaxy A5 2016
22 Points -29%
Honor 8
64 Points +106%
ZTE Axon 7
44.75 Points +44%

* ... smaller is better

Reading and writing data is one of the ZenFone 3's favorite tasks. It sometimes gets Honor's 8 in difficulties in sequential and random data transfer, and it can even surpass OnePlus' 3 in sequential write. Samsung's Galaxy A5 (2016) cannot quite keep up, but it still achieves an above-average write/read performance.

This is just as true for the ZenFone 3 when looking at the micro-SD performance. Although Asus' smartphone cannot fully exhaust the potential of our Toshiba Exceria Pro M401 (max. 95 MB/s read, max. 80 MB/s write), reference card, it achieves good rates with 79.2 MB/s in read and 50.1 MB/s in write.

AndroBench 3-5
Sequential Read 256KB (sort by value)
Asus Zenfone 3 ZE552KL
282 MB/s
OnePlus 3
408.7 MB/s +45%
Samsung Galaxy A5 2016
209.4 MB/s -26%
Honor 8
247.5 MB/s -12%
ZTE Axon 7
406.5 MB/s +44%
Sequential Write 256KB (sort by value)
Asus Zenfone 3 ZE552KL
188 MB/s
OnePlus 3
153.3 MB/s -18%
Samsung Galaxy A5 2016
60.4 MB/s -68%
Honor 8
119.3 MB/s -37%
ZTE Axon 7
150.9 MB/s -20%
Random Read 4KB (sort by value)
Asus Zenfone 3 ZE552KL
74 MB/s
OnePlus 3
137.6 MB/s +86%
Samsung Galaxy A5 2016
22.9 MB/s -69%
Honor 8
34.16 MB/s -54%
ZTE Axon 7
121.1 MB/s +64%
Random Write 4KB (sort by value)
Asus Zenfone 3 ZE552KL
7.4 MB/s
OnePlus 3
18.23 MB/s +146%
Samsung Galaxy A5 2016
11.2 MB/s +51%
Honor 8
31.5 MB/s +326%
ZTE Axon 7
16.22 MB/s +119%
Sequential Read 256KB SDCard (sort by value)
Asus Zenfone 3 ZE552KL
79.2 MB/s
Honor 8
53.7 MB/s -32%
ZTE Axon 7
78.4 MB/s -1%
Sequential Write 256KB SDCard (sort by value)
Asus Zenfone 3 ZE552KL
50.1 MB/s
Honor 8
23.59 MB/s -53%
ZTE Axon 7
51.3 MB/s +2%

Games

Asus' ZenFone 3 smoothly runs up-to-date Android games. Even hardware-driven games like "Asphalt 8: Airborne" can be played in a higher resolution without the frame rate coming close to the boundary of playable and jerky. The Full HD panel and its tremendous pixel density will also satisfy fans of strategy games, adventures, and MMOs. The ZenFone 3 even clearly displays small yet important image details, such as hit-points, hex grids or percentage values in the character screen, for example in the strategy role game "Banner Saga 2".

"Banner Saga 2"
"Banner Saga 2"
"Asphalt 8: Airborne"
"Asphalt 8: Airborne"
Asphalt 8: Airborne
 SettingsValue
 high29 fps
 very low29 fps

Emissions

Temperature

With a maximum temperature of 39.1 °C (102.4 °F), the ZenFone 3 is one of the smartphones that barely heat up even during full load. It is even just 31.6 °C (88.9 °F/back) and 33 °C (91.4 °F/front) on average in idling or when using standard apps. As the stress test with GFXBench illustrates, the ZenFone 3 not only pretends to run smoothly. The SoC did not throttle for potential thermal reasons but always stably maintained its high-performance even after running the T-Rex test 30 times.

GFXBench: Performance
GFXBench: Performance
GFXBench: Battery
GFXBench: Battery
GFXBench: Frametimes
GFXBench: Frametimes
Max. Load
 37.8 °C
100 F
38.2 °C
101 F
38.6 °C
101 F
 
 37.3 °C
99 F
36.8 °C
98 F
37.9 °C
100 F
 
 36 °C
97 F
36.3 °C
97 F
36.4 °C
98 F
 
Maximum: 38.6 °C = 101 F
Average: 37.3 °C = 99 F
34.6 °C
94 F
36.2 °C
97 F
39.1 °C
102 F
35.1 °C
95 F
35.9 °C
97 F
38 °C
100 F
34.5 °C
94 F
34.9 °C
95 F
36 °C
97 F
Maximum: 39.1 °C = 102 F
Average: 36 °C = 97 F
Power Supply (max.)  33 °C = 91 F | Room Temperature 21.5 °C = 71 F | Voltcraft IR-260
(±) The average temperature for the upper side under maximal load is 37.3 °C / 99 F, compared to the average of 32.8 °C / 91 F for the devices in the class Smartphone.
(+) The maximum temperature on the upper side is 38.6 °C / 101 F, compared to the average of 35.1 °C / 95 F, ranging from 21.9 to 63.2 °C for the class Smartphone.
(+) The bottom heats up to a maximum of 39.1 °C / 102 F, compared to the average of 33.9 °C / 93 F
(±) In idle usage, the average temperature for the upper side is 33 °C / 91 F, compared to the device average of 32.8 °C / 91 F.

Speaker

Speaker characteristics
Speaker characteristics

The mono speaker in the ZenFone 3 is situated on the USB port's right and it will thus not be covered when the smartphone is placed on a table. Up to 83.7 dB(A) can be extracted from the small speaker. As to the sound, the high tones prevail while mids are scarce and bass is heard only vaguely, at best. However, this is true for most smartphone sound systems, which only sound good when connecting a headset. Conveniently, this is part of the ZE552KL's accessories.

dB(A) 0102030405060708090Deep BassMiddle BassHigh BassLower RangeMidsHigher MidsLower HighsMid HighsUpper HighsSuper Highs2031.640.52525.432.93125.334.14032.932.95033.635.96331.633.68028.430.7100272612520.826.81602229.520021.336.925020.846.931521.251.840019.456.950019.561.663017.76480017.969.3100017.869.5125017.372.9160017.471.1200016.770.6250017.268.9315018.273.8400017.976500017.669.4630017.771.6800017.873.51000017.971.11250018.170.41600018.268.2SPL3083.7N1.356.5median 17.9median 69.3Delta1.410.131.636.725.432.825.32932.935.233.649.731.632.328.429.32725.720.8282239.121.346.820.855.621.259.419.463.219.569.417.772.517.973.717.875.117.375.917.476.116.777.917.277.518.277.717.976.517.673.717.768.217.861.217.953.518.156.118.2513087.11.366.1median 17.9median 68.21.41231.632.825.430.425.332.132.933.333.63631.630.128.427.82725.420.825.62229.121.339.620.848.321.254.219.456.819.559.117.758.117.961.117.864.417.365.817.467.416.770.317.27118.277.117.979.117.673.517.772.117.87117.966.418.157.518.253.13084.71.353.4median 17.9median 61.11.410.736.634.435.736.63032.332.43031.235.627.531.230.530.927.530.537.739.235.437.733.240.129.733.228.53029.228.526.32725.326.324.42724.124.430.926.42330.939.222.923.139.247.927.618.547.955.633.520.555.655.837.918.755.862.444.618.162.469.250.618.269.271.255.719.171.272.356.31772.371.156.617.371.172.753.317.472.775.95217.575.979.155.617.379.174.452.417.274.4714817.27171.348.217.271.382.458.717.682.478.555.317.778.573.849.817.873.866.543.11866.572.248.817.972.287.76629.987.768.919.11.368.9median 71.1median 48.8median 17.9median 71.18.710.61.68.740.136.832.440.1382731.33834.330.631.734.334.529.72634.544.138.139.444.140.529.736.240.53331.428.63326.827.625.426.826.924.421.326.93724.823.33745.529.522.545.551.636.222.451.657.341.721.357.359.746.618.459.766.452.517.566.468.45217.568.469.952.517.269.971.853.816.871.872.554.817.372.575.256.917.475.278.459.716.678.477.659.717.377.678.260.817.678.281.363.817.681.378.561.817.778.575.958.817.475.976.259.417.776.274.357.517.974.370.354.818.170.354.437.618.154.488.671.129.888.67325.81.373median 71.8median 53.8median 17.7median 71.810.910.71.710.9hearing rangehide median Pink NoiseAsus Zenfone 3 ZE552KLZTE Axon 7Honor 8Samsung Galaxy A5 2016OnePlus 3
Asus Zenfone 3 ZE552KL audio analysis

(+) | speakers can play relatively loud (83.7 dB)
Bass 100 - 315 Hz
(-) | nearly no bass - on average 33% lower than median
(±) | linearity of bass is average (9.9% delta to prev. frequency)
Mids 400 - 2000 Hz
(+) | balanced mids - only 4% away from median
(+) | mids are linear (5.7% delta to prev. frequency)
Highs 2 - 16 kHz
(+) | balanced highs - only 2.8% away from median
(+) | highs are linear (6.1% delta to prev. frequency)
Overall 100 - 16.000 Hz
(±) | linearity of overall sound is average (21.7% difference to median)
Compared to same class
» 38% of all tested devices in this class were better, 8% similar, 54% worse
» The best had a delta of 12%, average was 33%, worst was 134%
Compared to all devices tested
» 57% of all tested devices were better, 7% similar, 36% worse
» The best had a delta of 4%, average was 23%, worst was 134%

ZTE Axon 7 audio analysis

(+) | speakers can play relatively loud (87.1 dB)
Bass 100 - 315 Hz
(-) | nearly no bass - on average 25.8% lower than median
(±) | linearity of bass is average (12.3% delta to prev. frequency)
Mids 400 - 2000 Hz
(±) | higher mids - on average 6% higher than median
(+) | mids are linear (4.6% delta to prev. frequency)
Highs 2 - 16 kHz
(±) | higher highs - on average 7.7% higher than median
(±) | linearity of highs is average (7% delta to prev. frequency)
Overall 100 - 16.000 Hz
(±) | linearity of overall sound is average (24.4% difference to median)
Compared to same class
» 57% of all tested devices in this class were better, 8% similar, 35% worse
» The best had a delta of 12%, average was 33%, worst was 134%
Compared to all devices tested
» 73% of all tested devices were better, 6% similar, 21% worse
» The best had a delta of 4%, average was 23%, worst was 134%

Honor 8 audio analysis

(+) | speakers can play relatively loud (84.7 dB)
Bass 100 - 315 Hz
(-) | nearly no bass - on average 24% lower than median
(±) | linearity of bass is average (12.1% delta to prev. frequency)
Mids 400 - 2000 Hz
(+) | balanced mids - only 4.1% away from median
(+) | mids are linear (5.3% delta to prev. frequency)
Highs 2 - 16 kHz
(±) | higher highs - on average 11.8% higher than median
(±) | linearity of highs is average (7.2% delta to prev. frequency)
Overall 100 - 16.000 Hz
(±) | linearity of overall sound is average (28% difference to median)
Compared to same class
» 73% of all tested devices in this class were better, 5% similar, 22% worse
» The best had a delta of 12%, average was 33%, worst was 134%
Compared to all devices tested
» 84% of all tested devices were better, 3% similar, 13% worse
» The best had a delta of 4%, average was 23%, worst was 134%

Samsung Galaxy A5 2016 audio analysis

(+) | speakers can play relatively loud (87.7 dB)
Bass 100 - 315 Hz
(-) | nearly no bass - on average 33.7% lower than median
(±) | linearity of bass is average (11.1% delta to prev. frequency)
Mids 400 - 2000 Hz
(+) | balanced mids - only 4.2% away from median
(+) | mids are linear (5.4% delta to prev. frequency)
Highs 2 - 16 kHz
(+) | balanced highs - only 4.7% away from median
(±) | linearity of highs is average (8.4% delta to prev. frequency)
Overall 100 - 16.000 Hz
(±) | linearity of overall sound is average (22.1% difference to median)
Compared to same class
» 43% of all tested devices in this class were better, 8% similar, 49% worse
» The best had a delta of 12%, average was 33%, worst was 134%
Compared to all devices tested
» 62% of all tested devices were better, 7% similar, 32% worse
» The best had a delta of 4%, average was 23%, worst was 134%

OnePlus 3 audio analysis

(+) | speakers can play relatively loud (88.6 dB)
Bass 100 - 315 Hz
(-) | nearly no bass - on average 30.9% lower than median
(±) | linearity of bass is average (11.3% delta to prev. frequency)
Mids 400 - 2000 Hz
(+) | balanced mids - only 4.2% away from median
(+) | mids are linear (4.9% delta to prev. frequency)
Highs 2 - 16 kHz
(±) | higher highs - on average 5.6% higher than median
(+) | highs are linear (3.2% delta to prev. frequency)
Overall 100 - 16.000 Hz
(±) | linearity of overall sound is average (21.8% difference to median)
Compared to same class
» 41% of all tested devices in this class were better, 9% similar, 51% worse
» The best had a delta of 12%, average was 33%, worst was 134%
Compared to all devices tested
» 60% of all tested devices were better, 7% similar, 33% worse
» The best had a delta of 4%, average was 23%, worst was 134%

Frequency diagram in comparison (checkboxes above can be turned on/off!)

Energy Management

Power Consumption

The ZenFone 3 can fall back on a 3000 mAh, non-removable, lithium-ion battery, and it combines this with an overall low power consumption. Although the smartphone has the highest idle power consumption with 2.12 watts, it belongs to the top energy-savers with 5.46 watts when loaded. Samsung's Galaxy A5 (2016) is most frugal with 5.08 watts. The ZenFone 3 supports Quick Charge 3.0 and was fully recharged in roughly two hours in the test.

Power Consumption
Off / Standbydarklight 0.06 / 0.24 Watt
Idledarkmidlight 0.83 / 2.11 / 2.12 Watt
Load midlight 3.41 / 5.46 Watt
 color bar
Key: min: dark, med: mid, max: light        Metrahit Energy
Asus Zenfone 3 ZE552KL
3000 mAh
OnePlus 3
3000 mAh
Samsung Galaxy A5 2016
2900 mAh
Honor 8
3000 mAh
ZTE Axon 7
3250 mAh
Power Consumption
-12%
9%
-7%
-5%
Idle Minimum *
0.83
0.57
31%
0.96
-16%
0.78
6%
0.64
23%
Idle Average *
2.11
1.24
41%
1.64
22%
1.89
10%
0.84
60%
Idle Maximum *
2.12
1.36
36%
1.71
19%
2.02
5%
0.87
59%
Load Average *
3.41
5.92
-74%
2.98
13%
5.28
-55%
6.02
-77%
Load Maximum *
5.46
10.53
-93%
5.08
7%
5.44
-0%
10.45
-91%

* ... smaller is better

Battery Runtime

Although all comparison devices have a virtually identical battery capacity, they present very different runtimes. The ZenFone 3 and OnePlus' 3 are up front. The ZenFone 3 lasted over 13 hours in the practical Wi-Fi test, which should be enough for roughly two days of consistent browsing. Only OnePlus' 3 is better with exactly 14 hours among the comparison devices. The ZenFone played our Full HD test video ("Big Buck Bunny") over 15 hours before it was depleted. Even OnePlus' 3 cannot compete with that, but it still achieves a very good runtime of 14 hours and 7 minutes.

Battery Runtime
Idle (without WLAN, min brightness)
25h 02min
WiFi Websurfing
13h 17min
Big Buck Bunny H.264 1080p
15h 05min
Load (maximum brightness)
5h 52min
Asus Zenfone 3 ZE552KL
3000 mAh
OnePlus 3
3000 mAh
Samsung Galaxy A5 2016
2900 mAh
Honor 8
3000 mAh
ZTE Axon 7
3250 mAh
Battery Runtime
-9%
11%
-27%
-21%
Reader / Idle
1502
1338
-11%
2323
55%
1487
-1%
1735
16%
H.264
905
847
-6%
672
-26%
526
-42%
704
-22%
WiFi v1.3
797
840
5%
626
-21%
499
-37%
411
-48%
Load
352
268
-24%
483
37%
255
-28%
245
-30%

Pros

+ high-quality build
+ fingerprint sensor
+ very bright Full HD panel
+ Android 6.0
+ USB Type-C port
+ LTE and dual-SIM
+ long battery life
+ decent camera
+ Quick Charge 3.0

Cons

- poor WiFi performance
- LTE not at full speed
- lots of bloatware
- no App2SD
- no NFC
- Android keys not backlit

Verdict

In review: Asus Zenfone 3. Review sample courtesy of Asus Germany
In review: Asus Zenfone 3. Review sample courtesy of Asus Germany

Asus places a very stylish, 5.5-inch smartphone at the starting line that also convinces with inner values. With Qualcomm's Snapdragon 625 octa-core processor and 4 GB of RAM, the ZenFone has plenty of power that will be enough for all up-to-date applications and games. Furthermore, features like a very bright and viewing angle stable, Full HD panel and a 16-megapixel camera that shoots satisfactory photos are also present. The good configuration also includes LTE, a dual-SIM slot, a Type-C reversible USB port including Quick Charge technology, and a fingerprint scanner. The latest Android 6.0.1 Marshmallow, which Asus covers with the new version of its ZenUI interface, rounds off the successful package. The long battery life and low temperature development during use should not be left unmentioned.

Asus has created a designer piece with its ZenFone 3. The mid-range smartphone looks considerably more expensive than it actually is.

There is not much to criticize. The Android keys below the screen are not backlit and transferring data via Wi-Fi is more sluggish than fast. Asus is also a bit too generous with the software configuration and unnecessarily preloads many apps on the smartphone. In the test, we could not move apps to our micro-SD cards since they could not be formatted as internal storage.

Asus Zenfone 3 ZE552KL - 10/21/2016 v5.1 (old)
Manuel Masiero

Chassis
91%
Keyboard
72 / 75 → 96%
Pointing Device
89%
Connectivity
46 / 60 → 76%
Weight
92%
Battery
96%
Display
85%
Games Performance
32 / 63 → 51%
Application Performance
52 / 70 → 74%
Temperature
89%
Noise
100%
Audio
73 / 91 → 80%
Camera
72%
Average
76%
86%
Smartphone - Weighted Average

Price comparison

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Manuel Masiero, 2016-10-29 (Update: 2024-08-15)