What is the Asus Zenfone 6?

The Asus Zenfone 6 is the largest model in Asus’s new _phone_ line-up – a set of phones out to establish Asus as a real _phone_ brand. It gets you a 6-inch screen, and both a better processor and camera than the slightly smaller Zenfone 5.

We think the Zenfone 5 phone is pretty great, especially as it starts at just £150. The Zenfone 6 is a slightly tricker proposition as its size introduces a few usability issues, and it costs a fair bit more at £250 without 4G. But it’s ultimately a solid phone in almost every respect, and a good deal if you don’t mind about having a brand on the back your friends might turn their noses up at.

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Asus Zenfone 6 – Design

The Asus Zenfone 6 is a huge phone. There was no way around this one really – you can’t make a phone with a 6-inch screen and make it small.

As you have probably guessed by now from the score, we quite like the Zenfone 6, but this size is something you should consider seriously before buying. It means that when you hold the phone in one hand, you need to grip it with your fingertips and there’s really no room for manoeuvring the thing unless you get a second hand involved.

It’s more of a handful than a naughty three-year old with a sugar high and soon-to-be-diagnosed ADHD.
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The only way Asus could have made this slightly better is by trimming down the screen bezels as much as possible, a bit like the LG G3. We wouldn’t expect this from a company that’s pretty new to phones, and sure enough the Zenfone 6’s are pretty ordinary, resulting in a width almost 6mm greater than the Galaxy Note 4.

Yes, that phone has a smaller 5.7-inch screen, but it’s one of the few genuinely desirable big-screen alternatives out there. The Zenfone 6 isn’t exactly light at 196g either.

Aside from the largely unavoidable size issue, the Asus Zenfone 6 design is mostly a complete success. The look isn’t showy but has just enough little Asus inflections here to give the phone something bordering on an identity.

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You get a shiny bit of metal below the screen bearing a neat-looking finish of concentric circles - an Asus signature - a small Asus logo on back and front, and a simple, curved plastic rear.

In the Zenfone 5 we complained that the hardware soft keys looked a bit toy-like, a bit too large. However – strangely enough – they’re actually a bit smaller in this larger phone, giving them a more refined and sophisticated look.

The Zenfone 6’s design is not dynamic or particularly different. But from a company whose previous ‘phones’ like the Padfone 2 have been as ‘out there’ as the professor from Back to the Future, that’s no bad thing.

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We should also note that Asus has put some clear thought into making the Zenfone 6 as usable as it can be. Where in the Zenfone 5 the power button sits above the volume rocker, here it’s below, keeping it within reach of your thumb. It’s hardly a eureka moment, but it’s reassuring.

Build quality of the Zenfone 6 is commendable, even though the whole rear of the phone is a fairly standard moulded piece of plastic. It feels tough, there are no wide seams or creaky bits and the front of the phone is covered with Gorilla Glass 3.

This is the kind of toughened glass used in a great many high-end phones, and means you don’t really need a screen protector unless you really want to sell it on in perfect condition in a year or so. It’s highly scratch-resistant, and while it’s used in quite a lot of lower-cost phones these days – even the Motorola Moto E – it’s good to see Asus managed to fit such a large pane of the stuff into the budget.

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As well as looking and feeling really rather good, the Zenfone 6 is also a bit more flexible than an obvious rival on price, if not size: the Nexus 5. There’s a microSD card slot under that back cover, which is a great addition in a phone that really should be used as a little video buddy. If that isn't one of your primary considerations, why not get something smaller?

There are 8GB, 16GB and 32GB versions of the Zenfone 6 in existence, but the one we get in the UK at present has 16GB. There’s no 4G option at the moment, though. Given the £249 price, this is an issue.

Asus Zenfone 6 – Screen

However, let’s move onto what the Zenfone 6 is all about, the great big screen. It’s a 6-inch display, a middle ground between top-end phones like the Samsung Galaxy S5 and small tablets like the Nexus 7.

For some it’ll be the perfect compromise. You can still fit in your pocket (just about), but it’s also large enough to work as a decent little miniature TV/tablet.
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The is an issue, though. Resolution is just 720p, and for a phone of the Zenfone 6’s stature, that’s not a great deal.

The display looks a good deal softer than it would with a 1080p panel. It’s quite noticeable compared to something like the LG G2. There’s no ‘Retina’ level sharpness here, so be aware if that’s going to be a deal-breaker.

The clarity is still decent – 1,280 x 720 pixels at six inches gets you 245ppi – but it really does feel like things have moved on, even at this price.

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The Zenfone 6 screen is not obviously pixellated, but it is a bit soft

However, after using the phone for a week or so, we found that the actual results are still pretty good. As you tend to hold the phone a little further from your face, in normal use you’re not confronted by the lower-res display in a truly distracting way.

And sometimes having a bigger screen is better than having a smaller, sharper one. For example, to use as a little screen while you’re at the gym the Zenfone 6 is great. It’s also arguably superior for watching films on during a work commute than a 1080p 5-inch screen: although that’s open to debate.

Actual screen quality aside from pure sharpness is very good, if predictably not quite on the level of the top-end phones.
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The Asus Zenfone 6 uses an IPS panel, the kind used in most high-end phones. It offers good, mostly natural-looking colour and good viewing angles. These are just as important boxes to tick as the resolution one, and Asus also offers some customisation over the tone of the screen through Asus Splendid.

This app lets you alter the temperature and saturation of the screen. We reduced saturation a tad from the  out-of-box settings for a more natural look, but the slider’s there if you like your colours a little more intense than natural too.

Where the Asus Zenfone 6 reveals it doesn’t quite have a screen to match, say, the Xperia Z3, is with its slightly worse black level and a very slight colour tint when viewed from an angle. These are minor issues, though, and the people bothered by them are likely to also be turned off by the resolution.

The Zenfone 6 is in a tricky spot. There aren’t many high-profile 6-inch Android phones and last year’s ones like the Sony Xperia T2 Ultra have already slipped off shelves. We ended up pretty happy with the Zenfone 6’s screen, but it’s noticeably worse than some 5-inch alternatives that don’t cost much more – we’re talking about the Nexus 5 and LG G2. So make sure you need that extra inch.        

Asus Zenfone 6 – Software and ZenUI

The Asus Zenfone 6 runs Android 4.3 with the ZenUI, as seen in the other phones in the Zenfone range. This isn’t the latest version of Android, but differences between core versions of the system software are often steamrollered by changes made in the custom interfaces that sit on top anyway.

ZenUI doesn’t mess too much with the basic way Android works, but it does fiddle with some elements and applies a tweaked look to the entire system.

The alterations are largely identical to those of the Zenfone 4 and Zenfone 5. In some ways that's good, in others bad.
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For example, the Zenfone 6 has a split drop-down notifications bar. Flick down on the right of the screen and you get your settings controls and toggles. Flick on the left and you get your notifications.

In the 4-inch Zenfone 4 we thought this was a dreadful idea. But it makes perfect sense in the Zenfone 6, where you’re more than likely to have two hands involved when using the phone.

However, sharing the interface with much smaller phones often backfires for the Zenfone 6 too. There are zero optimisations specifically for the phone’s large screen size.
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In the apps menu, there are just four icons fit into the screen’s width, and both the home screen and settings menu are similarly languorous in their dealing with the giant 6-inch screen. The phone offers no reason, no justification for the 6-inch screen, so you’d better be prepared to find your own.

Asus Zenfone 6 – Apps and Performance

As we found in the Zenfone 5, while ZenUI doesn’t add masses to Android, it doesn’t detract from it hugely either. General performance is very good, with very little lag. Lower-cost phones with custom UIs often slow you down by having little pauses between traditions, or as widgets load. But here everything is quite smooth.

The Zenfone 6 doesn’t need a top-end processor to get this either. It uses the 2GHz Intel Atom Z2580 with 2GB of RAM. The generous RAM probably has a lot to do with the phone’s good performance, so make sure you get the 2GB edition (there are 1GB versions outside of the UK).

Intel’s Atom Z2580 seems to be a little bit faster than the Snapdragon 400 used on many mid-range phones these days, including the pricier big-screen Sony Xperia T3. In the Geekbench 3 benchmark, it scores 1303 points – more than Snapdragon 400 phones, but still way off Snapdragon 800 ones like the Nexus 5.

Digging a little deeper, the Intel Atom Z2580 is actually only a dual-core processor where every Android under the sun seems to be at least quad-core these days. However, Intel’s cores pack a real punch.
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It’s also worth noting that while the Zenfone 6 has a processor of the same series as the Zenfone 4 and Zenfone 5, it’s actually significantly more powerful than either thanks to its higher clock speed.

We found that, happily, it has enough power to play high-end games with little or no dips in performance. We have a feeling it might suffer if this was a 1080p phone, but the partnership of Z2580 and a 720p screen works well.

Asus Zenfone 6 – Camera

While a mid-price phone, the Asus Zenfone 6 has a reasonably high-end camera sensor. Its main camera uses a 13-megapixel camera, the sort of resolution seen in many of the top Android phones of 2013.

Where many phones use Sony camera sensors, we’re told the Asus Zenfone 6 actually has a Panasonic sensor of 1/3.06-inch size. That’s pretty good, especially when coupled with a fast f2.0 lens.

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Having been perfectly happy with the Zenfone 5’s camera, is it really worth upping the price to fit in this sensor? We’re not entirely convinced. But the Zenfone 6 does make a good everyday camera.

Whether down to the increase in sensor resolution or another property, the Zenfone 6 is a bit slower than the Zenfone 5, though. There’s a good 2-second delay between shots, which is far slower than the 13-megapixel camera of, for example, the Samsung Galaxy S4.

Asus does provide a Turbo burst mode, which shoots at about 5fps at reduced resolution, but it’s no real substitute for slightly faster normal shooting.

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You get loads of extra modes, all relayed quite simply and clearly in a custom Asus camera app. As well as essentials like HDR, panorama and low-light modes, there are some more fun ones too.

The depth of field mode blurs out the background by taking multiple shots to separate near objects from far-away ones, and Time Rewind is a sneaky burst mode that captures shots before and after you hit the shutter button, just in case you missed the right moment. Not all the modes work perfectly, but there's some fun to be had.

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It’s a neat camera app, and a good effort from Asus. But what about actual image quality?

It’s good. There seems to be a slight tendency to underexpose a little, but the level of fine detail is at times substantially superior to what you get with the 8-megapixel Zenfone 5. With good lighting, there’s loads of fine detail, which generally only succumbs to a bit of grain rather than the kind of dithering that makes an image look quite unnatural when you get down to pixel level.

The Zenfone 6 also offers better colour reproduction than the Zenfone 5, lacking that phone’s yellow bias in some shades.

There is a bit of purple fringing and a little bit of struggling with very high light contrast, but we think this is a very good camera, especially in a £250 phone that does not really base itself around the camera at all.

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Some of the additional modes are extremely useful too. HDR is great for combating the issues mentioned regarding underexposure and scenes with high light contrast, and Asus’s approach to low-light photography in the Zenfone 6 is really quite interesting.

The phone offers two low-light modes. There’s Night, which shoots at full resolution and merely tweaks the settings so they’re optimised for low-light shooting, and then there's the rather more interesting Low Light mode.

What this does is to downscale output from the Zenfone 6’s camera from 13 megapixels to just three megapixels, letting the camera harvest data from multiple sensor pixels to create a lower-resolution but more accurately-coloured final image. This, in tandem with mode increasing brightness/exposure compensation and a healthy dose of noise reduction, results in really quite clear photos even in terrible light conditions.

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The Low Light mode shot here is far, far better than the higher-res Night mode one

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Night mode does come in handy sometimes, though. Here the higer-res Night mode pic has retained a decent amount of detail.

They obviously don’t offer masses of detail, but then the finer details in low-light mobile photos are generally so ugly you wouldn’t want to crop into them anyway. Until we get mobile cameras that can provide results on par with a good compact like the Sony RX 100, this is what good low-light mobile photography is all about – clean photos with reasonably natural colours. It’s good work on Asus’s part.

Asus Zenfone 6 – Battery Life

One of the Asus Zenfone 6’s key features is its gigantic battery. It has a 3300mAh unit.

It’s even bigger than the Xperia Z2’s battery, and let’s not forget that this phone has a 720p screen – and of course the Xperia Z2 is a top battery performer. In our usual video test, which involves playing a 720p MP4 video until the battery dies, the Zenfone 6 lasted for just under 11 hours.

Given this phone has a 6-inch screen, that’s a good result. Sony’s phone still betters it, but the Zenfone 6 trounces the other phones in the Zenfone range. The Zenfone 4 didn’t even make it to five hours.
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It’s in normal use we saw the best results. With moderate use, you can get more than two days out of a charge. Three at a push, if you’re careful.

To provide some anecdotal evidence, on one day we started with only 67 per cent battery charge. However, with just that we made is through the day and up ’til lunchtime in the next. This is the sort of phone you really can be quite blasé about charging.

Like the Zenfone 5, though, you can’t remove the battery, meaning there’s no way to carry around a spare if you’re going to be away from a plug for a long time.

Asus Zenfone 6 – Call Quality and Sound Quality

Asus has also tried fairly hard with some other secondary elements of the phone too (it’s sad to think of battery life as secondary, but in phone marketing terms it is). The call speaker is unusually loud to cut through noisy environments.

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Having extra volume on tap is handy, but in pushing the presumably tiny driver as hard as the Zenfone 6 does the mid-range gets rather harsh at top volume. And, if you’re like us, your natural inclination is to max out the call volume as standard.

The internal speaker is a little less remarkable. It uses a single driver on the back, so there are no stereo shenanigans going on here. Sound quality is nothing remarkable, but passable.

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Should I buy the Asus Zenfone 6?

The question of whether you should buy the Asus Zenfone 6 needs to be countered with another: are you sure you really need or want the Zenfone 6? We’re not trying to dissuade you from upgrading your phone, but are you sure you want a 6-inch one?

Even the leap from a 5.5-inch phone is significant. And while we got used to the Zenfone 6’s size, we found the phone often ending up in a bag rather than a pocket because of its sheer size.

The Zenfone 6 does nothing in particular to help its cause either. It offers no software optimisation for the screen, and its resolution is no greater than the 4.5-inch Moto G. Of course, for things like gaming, video-watching and even browsing, a bigger screen is generally better.

Among 6-inch phones this is a top contender. Most of last year’s models have now been discontinued, there are few actual 6-inch alternatives, and it sells for a good deal less than phones like Sony Xperia T2 Ultra and HTC One Max were originally on sale for.

However, we can’t help but feels its efforts to be ‘more premium’ than the Zenfone 5 have backfired a tiny bit. At £250 the Zenfone 6 is a decent deal. But cut down the camera and CPU to the 5-inch version’s level, and get that price below £200 and you’d have a rather more remarkable phone. Still, Asus has done pretty well here.


Like any 6-inch phone the Asus Zenfone 6 is not for everyone, and its huge display could be sharper. But we quite like all its other aspects, particularly its very impressive battery life. Combined with a competitive price this makes for a decent phone-tablet hybrid.

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