Asus Zenfone 3 Ultra ZU680KL Smartphone Review

Asus Zenfone 3 Ultra ZU680KL is a 6.8-inch mega-sized smartphone. This is a high-end model in the big screen category. It has a lot of features that cannot be seen in mid-level smartphones. Mainly, the camera in Asus Zenfone 3 Ultra is one such excellently featured specification.

The features, specifications, and design are really fantastic in Asus Zenfone 3 Ultra. At the same time, the price is also high. Camera, Audio, and Battery are minds blowing in Asus Zenfone 3 Ultra. Some people may think, is this a tablet or smartphone. It is a smartphone in our point of view. Because it follows the pattern of the smartphone. In no way, it touched a tablet pattern, including the design. For many, a tablet-sized smartphone is a dream to have. The main reason is the big screen which gives us a better feel while watching videos or playing games or reading articles or books.

Asus Zenfone 3 Ultra ZU680KL Build Quality

Asus Zenfone 3 Ultra ZU680KL Review: Design and Build

The design of Asus Zenfone 3 Ultra looks sleek and stylish, unlike previous editions of Zenfone. The size is the defining factor above all others. Asus tried to make it look like a smartphone. That worked in few angles, but the size is something anyone can notice easily. One disappointment is, you can’t use Asus Zenfone 3 Ultra with one hand.

The metal frame of Asus Zenfone 3 Ultra is made of Aluminum alloy with CNC technology. Like many Android smartphones, Asus Zenfone 3 Ultra also has rounded corners and curvy sides. At the right side, we found the power button. At the top and bottom, a 3.5mm audio jack and USB type-C port are found. Surprisingly, the volume rockers are placed at the back side. It is also helpful in handling the volume rocker while holding the phone.

The rear camera with the flashlight is placed on the rear top left side. The front camera is on the front top while the fingerprint scanner found below the screen.

Asus Zenfone 3 Ultra ZU680KL Display


Though the screen size is big in Asus Zenfone 3 Ultra, the screen to body ratio is only 79%. The screen size is 6.8-inch with the full HD screen resolution. We felt the screen resolution could have been more than the full HD, as the screen size is bigger than the usual size. The display is made of IPS technology. The viewing angle is good even with the flat angle. Touch response is good, and it also works with 10-fingers at the same time.

The colors are clearly visible even in the daylight. Bluelight Filter is available within the device settings. One of the important features is the 4K TV-grade image processor which is available in the Tru2Life+ technology. This 4K video support justifies the big size screen. The screen is protected with Corning Gorilla Glass 4.

Asus Zenfone 3 Ultra ZU680KL Size

Hardware and Software Performance

Asus Zenfone 3 Ultra packs Qualcomm Snapdragon 652 Octa-core processor coupled with Adreno 510 GPU. This is quite good for mid-level performance. But with the hectic price of Asus Zenfone 3 Ultra, this is a low specification. At least a Snapdragon 820 could be better. There are two variants based on RAM available on the market. The lower variant has 3GB RAM, and the higher variant has 4GB RAM. It is safe to go with the 4GB RAM since it boosts the multitasking performance and also helps with the Android software updates in the future.

In our testing conditions, we feel some heating issues of the device while playing high-end games. The device doesn’t have volume controllers; it is a bit awkward to manage the volume everytime from the Settings panel.

The internal storage is either 64GB or 128GB. The 64GB storage is enough for many. But it depends on the user. The operating system of Asus Zenfone 3 Ultra is Android 6.0.1 Marshmallow which is rolled along with the Asus Zen UI 3.0. The CPU and older version of Android OS are something dragging the justification of the price tag.

In the audio, Asus did a great job with choosing high-class speakers and audio output. It has Dual5 magnet speakers with NXP smart AMP, Hi-Res audio 192KHz / 24-bit standard, DTS Headphone X with 7.1 Surround sound and dual internal mic.

Asus Zenfone 3 Ultra ZU680KL Features


The rear camera is seriously amazing in Asus Zenfone 3 Ultra. It has a 23MP camera in the rear with PixelMaster 3.0 app features. It includes a big list of features like HDR Pro, Beautification, 92MP Super Resolution, Children mode, Slow motion, etc. The video recording features have a 4K resolution at 24fps. The other video resolution is 1080p and 720p at 30 fps.

The front camera has an 8MP sensor with an 84-degree field of view. The PixelMaster 3.0 features available with the front camera too. The low light images are pretty good than expected.

Asus Zenfone 3 Ultra ZU680KL SIM Slots


The battery is a good thing in Asus Zenfone 3 Ultra ZU680KL. It has a capacity of 4600mAh. The Quick Charge 3.0 support helps this big battery to fill 60% in 45 minutes. The tests on the battery show nearly 2 days with casual use. On continuous heavy use, it powers the device nearly 5-8 hours. The heavy use here means the combined use of 4G internet, playing games, browsing, playing videos, etc. at the same time or in the background.


The price of Asus Zenfone 3 Ultra ZU680KL is about 700 Euros or 50000 Indian Rupees or 750 US Dollars. The price is the only issue. The device specifications are above mid-level. The CPU and the Display are the two main aspects that are not allowing us to list this smartphone under the high-end category. The cameras, RAM, Battery and other features are good and give us a feel of high-end.

Coming to the user point of view, the screen size plays a major role in the day to day use. A 6.8-inch screen is not for everyone. It is only for those who need big screen smartphone. At the same time, for those who need a tablet can check Asus Zenfone 3 Ultra ZU680KL, which has the tablet size, but a smartphone.

Asus Zenfone 3 Ultra ZU680KL Smartphone Review
7.8 Overall
Display Camera
Heating Issue No Volume Buttons
Build Quality8

Rahul is the Editor-in-Chief at Thetechhacker, Phone Opinions, and Ask Hacker. After realizing an obsession with technology, he left his job career to write about technology.

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