Asus Zenfone 4 Review: In Depth

We review the Asus Zenfone 4, a £99 Android handset that’s pretty small but still packs in some decent features, including a nippy Intel processor and 5-megapixel camera.

It’s never been a better time to be a skint smartphone lover, with some seriously good handsets hitting the £100-and-under mark. Just check out our best phones for under £100 piece if you don’t believe us.

You can nab yourself a 4G phone like the EE Kestrel, or a cool and colourful Nokia Lumia handset, but they all still pale in comparison to the mighty Motorola Moto G, with its glorious 720p screen, quad-core power and full Android KitKat. But another contender for the value crown has just strode into town: the Asus Zenfone 4, a £99 Intel-powered phone that packs some serious specs to rival the Moto G.

So does the Zenfone 4 deliver, and is it the first Moto G beater?

Asus Zenfone 4 design: Four inches of fun

The Zenfone 4 is the first 4-inch smartphone we’ve fiddled with in a while, and a domain almost entirely ruled by Apple for now (until that 4.7-inch iPhone 6 emerges). Even the latest budgety handsets tend to be 4.3 to 4.5-inches now.

As you’d expect, the Zenfone 4 fits neatly into your palm and is easy as pie to operate with a single hand, swiping your thumb across the screen. At 115g it’s still reasonably hefty, so it doesn’t feel like a toy, and the curved rear gives a comfortable grip.

Many rival budget phones (such as the Moto E and the Lumia 630) rock a colourful design, and Asus hasn’t bucked the trend. The Zenfone 4 comes in a range of colours, including red, yellow and blue, as well as the usual boring black and white. You know, in case you don’t like fun.

The back cover is removable, so you could swap colours feasibly, and inside you’ll find a microSD memory card slot as well as a SIM card slot. The 1600mAh battery is also free to prise out and replace, which as it turns out might be a vital feature…

Overall, the Zenfone 4 is a decent looking device, and the jutting lip might add a bit of bulk but it’s not intrusive. We kind of wish the colour stretched from the back around to that lip, so the front wasn’t just a sheet of black, but you can’t have everything.

Asus Zenfone 4 screen and media: Small but satisfying

That 4-inch panel is coated with Corning Gorilla Glass 3, which helps to protect it from scratches and other scuffs. It seems hardy enough to soak up most punishment, but a tiny scratch did somehow appear near the top of the display at some point during our review. It’s only a light one, but it’s still mildly distracting.

As for the panel itself, it’s just about bright enough to cancel out annoying sun glare, so it’s easy to read when you’re out and about; but only if you crank it up to maximum brightness. Viewing angles are decent, and we didn’t see any weird graphical glitches.

Sadly some of the Zenfone 4’s rivals, such as the Moto G and Lumia 630, sport more vibrant screens with better contrast and cleaner whites. That said, colours aren’t exactly washed out on the Zenfone, and there is a ‘Vivid Mode’ which allows you to mess around with colour temperature and saturation levels until you’re happy.

The Zenfone 4 also boasts a sharper panel than the Lumia 630’s thanks to its 800×480 resolution, even if it can’t match the same supremely crisp 720p visuals of the Moto G.

Of course, watching movies on the tiny screen isn’t exactly an Imax-style experience, and you might want to look at bigger phones if you plan on chilling with videos on your commute.

Asus Zenfone 4 user experience: ZenUI

You might think the 4-inch screen might make typing tricky, especially given how used we personally are to ridiculously huge screens (we came straight to the Zenfone 4 from the LG G3, with its enormous 5.5-incher). Good news, though, as we had no trouble bashing out emails and texts on that dinky display. We didn’t even get vicious hand cramp. The Asus keyboard has built-in typo correction if your fingertips do stray, plus next word prediction, so we actually managed a decent speed after very little time with the phone.

As for the rest of the interface, Android 4.3 has been mixed up with Asus’ ZenUI, and for the most part we like it. We don’t quite get Zen levels of satisfaction, but the handy shortcut menu lets you throw in as many power settings as you like (Bluetooth, Wi-Fi etc) and the lock screen has some handy shortcuts of its own, plus an overview of any upcoming events you’ve got planned.

There’s a fair bit of crapware packed away on the Zenfone 4, but some helpful apps too. Android newcomers will probably welcome the file manager and setup wizard, plus the likes of the tasks app is handy if you don’t already have a preferred alternative. But the likes of Mirror and Omlet Chat are simply space wasters that are crying out for an uninstall.

Asus Zenfone 4 performance and battery life: And it was going so well

Asus bigged up the fact that the Zenfone 4 packs an Intel Atom processor (Z2520, running at 1.2GHz, if you’re into tech specs) rather than the usual SnapDragon efforts usually found in smartphones. Opinions seem rather split on the Atom (pun entirely intended), but in the few days we’ve played with the Zenfone we’ve been suitably impressed. It’s a slick experience – the OS runs smoothly, apps generally load in no more than a second or two, and even the latest games play with a decent frame rate.

If you want speedy 4G web browsing, however, the Zenfone 4 isn’t the cheapy phone for you. There’s no LTE support here, so you’ll need to look at the EE Kestrel instead.

Unfortunately, the Zenfone 4 has not so much an Achilles Heel but a full-on Achilles Leg. The major weakness is its battery life, which is truly woeful.

If you keep the phone’s display on high brightness and occasionally check emails or browse the web, you can be damned sure the battery will be dead before the end of the day. When the screen is turned on you can practically watch the battery meter drain down, and if you’re streaming video, you’ll be lucky to get even three measly hours of life from a single charge. Compared to the average of five hours, that’s seriously short.

We just about managed to squeeze a day of life from the Zenfone 4 if we dimmed the screen right down and limited ourselves to only very brief texting and email checks, but you simply shouldn’t have to resort to these actions with a 4-inch phone.

Asus Zenfone 4 camera:

The 5-megapixel ‘PixelMaster’ camera is a respectable budget snapper that packs a ton of features in, as you’d expect from a much more expensive smartphone like the Samsung Galaxy S5. Of course, these features can be a little hit-and-miss.


Starting with everyday snaps, we were happy with the shots we got from the Zenfone 4 on auto mode. Occasionally they can look a little soft when you check them out on a TV, with some patches blurring inexplicably, and strong colours seem to confuse the lens. Still, low-light shots are pleasingly bright (just as well as there’s no flash) and the HDR mode helps in tricky lighting situations outside.


But the Zenfone 4 won’t just let you snap photos and 1080p video. You can also record your own GIFs, and remove photo bombers in post-production. In fact, the Zenfone 4 packs many of the same features found on the Galaxy S5 and other premium handsets, including Time Rewind and even Depth of Field.

Sadly we experienced mixed results with a few of these modes. Depth of Field often produced weird shots with random blurring, and the Smart Remove mode for taking out background lingerers only works if the offender is moving at pace.

Still, we did enjoy the Time Lapse mode, something we’ve only previously seen on iOS 8.

As for selfies, there’s not only a front-facing lens but also a special selfie mode that uses the rear camera. Just set the number of faces to detect, swivel the phone around, and if you’re lucky (and in a well-lit environment) the Zenfone might actually take a picture.

Asus Zenfone 4 verdict

The Zenfone 4 is a frustrating tale of two phones. There’s the compact, user-friendly 4-inch smartphone that sports a colourful design, slick performance and a neat interface. Then there’s the phone that struggles to last from sunrise to sunset, that has you keeping one eye permanently on that ever-decreasing battery meter.

So while the Zenfone 4 can’t quite beat the mighty Moto G’s all-round experience, it’s still a nifty little 4-incher that has a lot to offer casual users.

Read next: Our full round-up of the new Asus Zenfone 4, 5 and 6

Exit mobile version