ZenFone 6 preview: ASUS reinvents itself with stock Android, 5,000mAh battery + flip camera

In recent years, the ASUS ZenFone line has been characterized by overbearing software, a bewildering number of often superfluous features, and copycat design language. After first seeing last year's ZenFone 5 series, my initial impressions were of a phone whose only goal was to be a cheaper iPhone lookalike, while also bludgeoning me with nonsensical faux-AI features. It did little to convince me why I should care about an ASUS phone specifically.

A year later, at a pre-launch meeting at the company's headquarters in Taipei, Taiwan, it was clear to me that a lot had changed. ASUS has a new design language, all of its own. It has a new software strategy built around near-stock Android and quick updates. And it has a fresh approach to the great technical challenge of a 2019 smartphone -- how to banish the display notch.

In doing so, it introduces a new rake on smartphone photography, with a mechanical flip camera serving as both the rear shooter and selfie snapper.

And, fellow phone nerds, I am pleased to report that it also has a humongous battery and a 3.5mm headphone jack.

The core specs of the ZenFone 6 are everything a phone nerd could want in a 2019 flagship.

After ASUS's surprising success with the gamer-focused ROG Phone, it seems, the company is doubling down on power-user phones. Or, more accurately, a single power-user phone. Unlike past generations of ZenFone, there's only one major SKU of ZenFone 6. It's got a Snapdragon 855 processor, up to 8GB of RAM and 256GB of storage, and a 5,000mAh battery rechargeable via Qualcomm Quick Charge 4.

ASUS was upfront about the trade-offs involved in packing such a huge battery inside a relatively normal-sized smartphone. In a nutshell, you can have a big battery, or a fast-charging battery in the same physical space, but not both. The company could've delivered faster charging -- up to 40W, matching Huawei's SuperCharge spec -- with a reduced 4,000mAh capacity. Instead, it chose to pack in 5,000mAh, but with 18W charging via the Quick Charge 4 standard.

ASUS ZenFone 6 specifications

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DesignCorning Gorilla Glass 6, 3D Curved Glass with NMT technology
Display6.4-inch Full HD+ IPS LCD, 19.5:9, 91% screen-to-body ratio, 100% DCI-P3 colorspace
CPUSnapdragon 855
GPUAdreno 640
Main Camera48MP Sony IMX586, f/1.79
Second Camera13MP 125-degree ultrawide
Video Recording4K UHD, 3-axis EIS
Wireless802.11 a/b/g/n/ac 2x2 MIMO, WiFi-Direct, Bluetooth 5.0
SIM/SDTriple slots: 2X nanoSIM, 1X microSD
OSAndroid 9 Pie, ZenUI 6
Battery5,000mAh, 18W Quick Charge 4
ColorsMidnight Black, Twilight Silver

ASUS ZenFone 6

The logic, with such a huge cell, is that you'll only ever need to worry about charging overnight anyway. ASUS quotes up to 21 hours of continuous Wi-Fi browsing, or 2 days of usage.

Despite its giant battery, the ZenFone 6 isn't excessively weighty, at 190 grams. It's not exactly svelte, but it's also not a total dinner plate like the Huawei Mate 20 X, the Chinese company's 7-inch hybrid device that also totes battery of the same size.

The rear of the ZenFone 6 is pretty unconventional. A great big wedge cut into the chassis to accommodate the device's standout hardware feature, its dual flip camera. This is how ASUS is able to avoid including either a screen notch or large front bezels in the phone. The trade-off, of course, is a back panel that looks far less sleek than the competition.

The ZenFone's design is unconventional, to say the least.

The glass back and sides are vaguely reminiscent of a more sensible take on the ROG Phone's design. The branding is more subdued, but typical ASUS flairs remain, such as a reflective, laser-etched pattern under the glass, and chamfered edges around the metal frame. There's also a regular capacitive fingerprint scanner lurking back there, a fine alternative to the still imperfect crop of in-display fingerprint sensors.

ASUS's customizable smart key is back, too, and by default fires up Google Assistant -- though as the name suggests, the key is entirely configurable.

ZenFone 6

Aside from the wacky new flip camera, the design feels like a bit of a throwback in smartphone design terms. (Chamfers are a little bit 2015, after all.) But the front face of the ZenFone 6 is rooted firmly in the present. Although its screen borders aren't as tiny as some rivals, like the recently unveiled OnePlus 7 Pro, the new phone's borders are reasonably svelte, save for the small chin down below.

The front is dominated by a 6.4-inch IPS LCD panel that seems a tad out of place in a market dominated by AMOLEDs, but which nevertheless looks great. The panel features colors of equal vibrance to the leading OLED phone screens, and is easily visible in direct sunlight. Although it's "only" a Full HD+ panel, the extra subpixel density afforded by it being an LCD means the lower resolution isn't as noticeable as it might be on an AMOLED display.

ZenFone 6

ASUS's ZenUI 6 shares branding with its earlier software efforts, but the design language, look and feel of the new UI represent a clean break. No more bright, goofy colors or bloatware. Aside from Facebook, only the ASUS Data Transfer app and MyASUS account manager app are loaded on our ZenFone 6 review device. And as far as the interface goes, ASUS has pivoted hard towards stock Android. It's not quite Android One, but it's close enough that most people won't be able to tell the difference.

Incidentally, the decision to not make this an Android One device was a pragmatic one, ASUS reps tell AC. Android One has its own somewhat restrictive set of requirements, and existing outside this ecosystem allows ASUS to move faster when it comes to rolling out new software.

ASUS is shipping near stock Android, and plans to be one of the first to Android Q.

ZenUI 6

The company is also keen to convey its seriousness about software updates, with all its major 2018 devices now running Android Pie, and a faster cadence for updates to Android Q planned for this year. Like the ZenFone 5Z, the ZenFone 6 will join the Android Beta Program in the near future. The company plans to be "one of the first" to update to Q -- which is admittedly vague, but I took to mean timings closer to OnePlus which shipped Android Pie in September, than Samsung, which shipped it in January.

So this isn't quite a pixel-for-pixel recreation of Google's Android UI, but it's extremely close. And where ASUS has done its own thing, the UI now matches Google's Material Theme, with blues and whites dominating the color palette. Since this is a fairly hefty phone, one-handed usability has also been a major software focus. ASUS has its own one-handed mode, activated with a double-tap of the home key. And subtle changes to the ASUS launcher, dialer and clock apps, among others, relocate key controls down to the lower portion of the screen

ZenUI 6

A system-wide dark mode is available too, though with an LCD display, ZenFone 6 users won't see the same battery-saving benefits as OLED phones. In any case, the company says it'll work its dark mode implementation into Google's dark theme when it ships in Android Q.

ZenUI 6 has more than superficial changes, though. ASUS claims its intelligent memory management and optimization of the Android framework help the ZenFone 6 perform common tasks, like opening a recent photo in the gallery app, quicker than the Android competition. I can't say I've noticed a major difference in responsiveness compared to the Huawei P30 Pro and OnePlus 7 Pro I've been using recently. On the other hand, in my brief time with it so far, the ZenFone 6 has delivered silky-smooth performance and quick app load times.

The bottom line on software is pretty simple: ASUS knows users like its features, just not the overbearing UI that surrounded them. The remedy in the ZenFone 6 is an obvious but welcome solution: Fast, stock software with helpful additions here and there. In that way, ZenUI has evolved to become much more like OnePlus's OxygenOS than anything else out there.


ASUS's bonkers new flip camera took a ton of great deal of engineering work.

The camera is the most complex part of the ZenFone 6, and the phone's most eye-catching feature in a market dominated by interchangeable glass slabs. The main advantage of a flip camera like this is that instead of using a lower-quality front-facer, you get to take selfies with the high-quality sensors and lenses usually reserved for rear-facing photography.

In ASUS's case, these cameras consist of a 48-megapixel Sony IMX 586 lens (same as the OnePlus 7 Pro, only minus OIS and with a slightly slower f/1.8 lens), and a 13-megapixel ultrawide camera at f/2.4. The main shooter features the same quad bayer technology as other devices.

The main disadvantage, or at least the main technical challenge, comes with fitting moving parts within a smartphone that's likely to get dropped, dinged up and generally abused over the course of several years of ownership.

ASUS's engineers have toughened the flip camera module with a new amorphous alloy, making it more resistant to knocks and scrapes. Meanwhile the hinge consists of a customized stepper motor for smooth motion -- which is important, since the camera can be used not just facing the front or back, but at any angle in between. Swiping up on the camera switch button in the camera app gives you free control over the rotation, which allows for some unique photographic opportunities.

A phone camera that can move has also opened up a handful of unique shooting modes. For example, ASUS has built in a motion tracking video feature, where the camera will automatically move to track the subject if it moves out of frame. What's more, Auto Panorama allows you to stand still and rely on the motor to do the work for you.

Auto Panorama

And yes, the front camera can be used for face unlock too, though doing so feels pretty weird, and the module definitely takes longer to pop up than the OnePlus 7 Pro's small selfie module.

Speaking of which, just like OnePlus and the handful of other pop-up cameras we've seen, the module will retract into the phone if the gyroscope detects a drop, preventing damage to the hinge. Unfortunately, though, there's no water resistance, on account of the complex problem of sealing up the hinge area.

The big question at this stage is whether the ZenFone 6's camera will compliment its impressive flip camera engineering with high-quality photos to compete with the likes of OnePlus and Huawei. To start with, the lack of a telephoto lens puts it at a disadvantage, and overall, my early impressions after a couple days with the phone are of a competent but not amazing main shooter. The final verdict will have to wait for our full review.

ZenFone 6

ASUS's change of approach with the ZenFone 6 is welcome. As a result, it's a genuinely interesting device from a company whose smartphone offerings haven't exactly wowed us lately. The bizarre new flip camera might be what turns consumers heads in the coming weeks, but the thing that should keep them interested in this phone is the solid loadout of specs, extraordinarily large battery, speedy performance and the company's new commitment to stock Android in ZenUI 6.

Price is also going be a big factor. If the ZenFone 6 tries to go toe-to-toe with the OnePlus 7 Pro, it might struggle. But priced against an Honor View 20 or (non-Pro) OnePlus 7, this could be a great device for enthusiasts who don't want to break the bank on a new flagship.

We'll update this article with pricing and availability information once it's revealed.

More: The ZenFone 6 designs that ASUS left on the cutting room floor

Alex Dobie
Executive Editor

Alex was with Android Central for over a decade, producing written and video content for the site, and served as global Executive Editor from 2016 to 2022.