Asus Zenfone 4




  • Decent internal storage at the price
  • Fair day-to-day performance
  • Colourful design
  • Feature-packed camera app


  • Rubbish battery life
  • Non-IPS screen
  • Interface fiddly in places

Key Features

  • Review Price: £99.99
  • Intel Atom Z2520 1.2GHz CPU
  • 1GB RAM
  • Android 4.3 with ZenUI
  • 4-inch 480 x 800 LCD screen
  • 8GB storage

What is the Asus Zenfone 4?

The Asus Zenfone 4 is Asus’s first attempt at a mainstream budget phone. It has made a few oddball mobiles to date, like the Asus Fonepad and Padfone 2 hybrids, but this one is downright normal.

It costs just £99 SIM-free, but can Asus compete with budget giants like the Motorola Moto G with virtually no experience in the area? Predictably, the Asus Zenfone 4 is less than perfect, and quite troubled in some areas. However, it’s far from the worst budget phone out there.
Zenfone 4 19

Asus Zenfone 4 – Design

The Asus Zenfone 4 is a cute little phone that is a pretty good design effort from a company that doesn’t have a huge amount of experience in the field of phone-making. It’s plastic, has easy curves and features just slight tweaks from an archetypal small handset design.

First, you get colourful backs. Ours is yellow, and it has a nice, slightly metallic shade. We got to see it next to the yellow Motorola Moto G, and it lacks that phone’s slightly sickly green tinge. It’s nice. Other colours include pinkish red, blue, white and black. The more colourful Zenfones all have a hint of pastel to their shades to avoid looking too brash.

Asus has also plugged one of its design signatures into the Zenfone 4 – the concentric circles texture seen in its Zenbook laptops. There’s a bit below the screen with this look. It’s normally applied to aluminium in Asus’s other gear, but this being a £99 phone, it’s plastic.

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It’s hard to spot in this shot, but the bottom lip is a bit shiny

The Zenfone 4 is also small even among budget phones. Thanks to a 4.0-inch screen it’s a good deal dinkier than the Moto G or EE Kestrel, which are two of our top picks around the £100 mark.

It’s not a slim phone, though. At 11.5mm thick it has the classic design trait of the small low-cost phone – small footprint, but a bit chunky around the middle. Ergonomically it’s pretty good, though. It’s small enough to put all the buttons within easy finger’s reach, and both the volume rocker and power button sit on the right edge.
Zenfone 4 21

The back of the Zenfone 4 pulls off easily, with a little recessed bit on the edge to help out. The back cover hides the microSIM slot and the microSD memory card slot. However, some of you won’t need a memory card as the UK version has as much as you could expect at the price.

You get 8GB internal memory. That’s not masses of room, but many £100 phones have 4GB. That said, the EE Kestrel and baseline Motorola Moto G have 8GB too. It’s not enough to store a lot of movies on, but having the extra 4GB of storage makes it a lot easier to fit in a few storage-heavy 3D games and still have enough room for a couple of dozen albums of music.

Zenfone 4 33

Asus Zenfone 4 – Screen

Of course a 4-inch screen like the Asus Zenfone 4’s is never going to be top-class as a gaming machine. While the iPhone 5S only has a 4-inch screen and is a positive gaming factory, we’re spoilt with Android. These days it’s not hard to get a 4.5-inch screen phone at this price.

It’s not a top-notch screen either, as it uses a TN-style panel rather than an IPS one. The main issue with TN screens, which are still used widely in lower-cost laptops and monitors, is that they suffer from contrast shift. Tilt the Asus Zenfone 4 back or forward at all, and you can see effect of it – tilt it back and contrast reduces, forward and it increases.

This sort of inconsistent screen experience is one of the Zenfone 4’s biggest issues.

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Zenfone 4 37

For a TN-type screen it’s not too bad, though. Colours are nice and bold, and while the screen is a bit recessed (rather than laminated) – something that affects how contrasty the screen appears in sunlight – contrast is otherwise reasonable.

Like Asus’s tablets, the Zenfone 4 also gives you control over the character of the display using an app called Asus Splendid. It lets you tweak the colour temperature of the screen, and its saturation.  You can also change the hue completely (turn reds into greens etc.) but we’re yet to find a good use for this.

Splendid lets you tune the colours, to make them as vivid or subdued as you like, and you hardly ever get this control in a £100 phone. It’s a nice touch.
Zenfone 4 23

However, there are a few other issues with the screen too. Resolution is only just passable at 800 x 480. Pixel density is 233ppi, which is still significantly bettered at the price by the £80 Moto E (256ppi), the Moto G (326ppi) and EE Kestrel (245ppi). All of these screens are a good deal better than the Zenfone 4’s display – they’re higher-res and use superior IPS panels.

In use, there’s another annoyance too. The Asus Zenfone 4 has no automatic brightness setting, meaning you need to manually alter the phone’s brightness slider whenever you go from indoors to outdoors. We find this pretty annoying, because the reflective screen needs to be at max brightness for outdoors use, but the battery isn’t good enough to make keeping it at this level remotely viable.

Ultimately, the Zenfone 4 screen is a disappointment in a few areas.

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