Asus Zenfone 5z review: Sleek, swift and power-packed mid-range smartphone

The Zenfone 5z, a premium smartphone from the stable of Taiwanese computer peripheral manufacturer Asus, boasts premium innards, coupled with system-wide artificial intelligence (AI) capabilities that learn, adapt and customise user experience based on machine-learning algorithms. Importantly, it is the phone’s starting price of Rs 29,999 that makes it an interesting proposition in the mid-range flagship smartphone segment.

First unveiled at the Mobile World Congress, the Zenfone 5z was the first Android-based smartphone to showcase iPhone X-inspired notch-based screen. However, other smartphone manufacturers rolled out similar offerings before Asus, rendering the Zenfone 5z a late comer to the party. But the phone’s user interface is optimised to support the notch – be it in apps or otherwise – which makes it one of the few Android offerings with a usable notch screen.


Screen and multimedia

The screen is an eye-candy – bright, vivid and full of colours. Though it is of the IPS breed, it offers deep blacks and good viewing angles which puts it on a par with some of the best LCD screens that we have seen in smartphones, including those of HTC. The screen is HDR-compliant which boosts colours while playing HDR content – it is the only mid-range flagship at present that has this feature.

In terms of multimedia playback, like any other notch-based smartphone, the screen supports operations with or without the notch. However, unlike any other mid-range smartphone, the option to enable or disable notch pops up on the navigation bar as soon as video content is played, either through in-built video player or apps like Amazon Prime Videos, YouTube, Netflix, etc. This makes it easier to switch between notch and without notch operations without getting into the settings menu.

The phone is also the only mid-range flagship to sport dual stereo speakers powered by a dedicated dual AMP for each unit. The speakers are loud and clear but not as refined as the one found in premium smartphones like the HTC U11+, Samsung Galaxy S9+ or Apple iPhone X. While the output remains loud and audible in most cases, the software-backed outdoor mode boosts the volume levels even further.


The Zenfone 5z has a dual camera set-up on the back that uses a 12-megapixel primary sensor of f/1.8 aperture and an 8MP wide-angle lens. On the front, there is an 8MP camera for selfies. The cameras in the Zenfone 5z are powered by an AI engine that detects scenes and customises the settings automatically.

The 12MP primary sensor on the rear supports 4-axis optical image stabilisation (OIS), which comes handy during low-light photography to capture long exposure shots without a tripod. The camera takes detailed shots and the built-in PRO mode gives a complete manual control over granular settings like ISO, shutter speed, focus, etc.

On the other hand, the 8MP secondary sensor with a 120-degree field of view takes wide-angle shots with more objects in frame. However, due to lack of telephoto lens, the phone lacks 2x optical zoom capabilities, and the phone’s zoom maxes out at 4x – all digital. The phone supports portrait mode and it is one of the smartphones that do proper segmentation of object and background, allowing it to take proper bokeh shots with no artificial halos around focus objects.

The 8MP selfie camera takes satisfactory shots, but struggles during low-light conditions. However, the picture quality is on a par with other smartphones in the same segment.


The Zenfone 5z is powered by Qualcomm Snapdragon 845 system-on-chip, paired with either 6 GB of RAM and 64 GB and 128 GB internal storage or 8 GB of RAM and 256 GB of internal storage. The phone features a hybrid SIM slot, which supports a microSD card of up to 512 GB. The phone boots Android Oreo covered under ZenUI 5.0, a major improvement to the previous iteration of the operating system.

The operating system is also fuelled by the AI engine, which learns from usage patterns to improve apps’ background activity and speeds up launch time. The performance is swift, with no signs of lag or stutter. Apps runs optimally and the most used ones open in a jiffy. Importantly, the bloatware has reduced to only a handful of apps.

The phone processes heavy apps without any sign of weakness. It also runs heavy games like Asphalt 8: Airborne, Asphalt Xtreme: Rally Racing, Need for Speed No Limits, etc, with full SFX effects and without heating up or losing frame rate.


The Zenfone 5z is powered by a moderate 3,300 mAh battery, which keeps the show going for a day. In the first few days, the battery might show inconsistent results, given that the AI engine responsible for optimising the battery usage remains passive and learns usage patterns in the background. However, after a few recharge cycles, the phone’s battery shows consistent results.

Speaking of charging, the phone supports a quick charger powered by the AI engine. It charges up as quickly as the OnePlus devices, which have the best charging time in the industry – thanks to the OnePlus dash-charging technology. The charging time in the Zenfone 5z varies from an hour to one-and-a-half hours, based on how the AI engine understands the requirements. Putting the phone on overnight charge is not a problem, as the AI engine charges the battery quickly, by up to 80 per cent, and then turns on the intelligent mode that charges slowly. 


Priced at Rs 29,999 for the base model with 6 GB of RAM and 64 GB of internal storage, the Zenfone 5z is a power-packed proposition in the mid-range flagship segment. The phone has strengths in all areas and is the only smartphone close to challenging the OnePlus dominance – as seen by an earlier Business Standard poll. The phone’s AI engine is more than a gimmick and its system-wide implementation adds to the smooth performance of the smartphone. However, the phone would have been a complete package if it had water resistance rating and wireless charging capabilities.