PERFORMANCE & BATTERY LIFE
The core hardware is another area certain to raise a few eyebrows. This phone costs as much as the OnePlus 5, but has a much less powerful processor.
It goes with the Snapdragon 630, an up-to-date but ultimately mid-range CPU used in some significantly cheaper phones. This CPU has eight cores, but they’re all the Cortex-A53 kind, the same used in the Moto G5.
However, just about no-one is going to notice this is a lower-power phone. High-end games run almost bizarrely well, with frame rates in Asphalt 8 looking very smooth, making it great fun to play. One of the Snapdragon 630’s upgrades is a faster graphics chip, the Adreno 508, and it shows.
This is a very good phone for gamers. In Geekbench 4, though, the ZenFone 4 scores 4137 points. The Honor 9 manages around 6000.
ZenUI also adds a gamer overlay that lets you record footage and lets you programme-in macros like a pro mobile gamer. If they exist. I find this floating bar more distracting than anything else, but you can disable it if you like.
This is a tough one. You can get more power for your money from the Honor 9 or OnePlus 5. But, frankly, I don’t miss it.
The ZenFone 4's 3300mAh sounds massive, and sure enough I’ve found the phone lasts a full day - even with an hour’s messing about online looking for things to do at the weekend, a few hours of podcasts and normal app use.
With very light use you should be able to get most of the way to two days’ use. However, if you’re into mobiles deep enough to be considering a ZenFone, you probably use a bit more than just WhatsApp. Consider this a phone that’ll last a solid day with a bit in the tank for the next morning.
An hour of Real Racing 3 takes 15% off the battery level. That’s not too bad at all, suggesting you’ll get over 6.5 hours of gaming off a full charge.
The ZenFone 4 offers “fast charging” but the slowest kind that can still make this claim valid. It’s a 10W charger, so doesn’t rocket up to 80% charge in a flash. It’s not a match for the OnePlus 5.
Its brain may not have class-leading chops, but the camera specs are hard to argue with. The ZenFone 4 uses a primary 12MP Sony sensor on the back with phase detection autofocus and, still a killer feature for night photography, optical image stabilisation.
This teams-up with a lower-end 8-megapixel wide angle camera with a 120-degree field of view. You trade away image quality a bit and the wide camera is pretty useless at night, but most of the time you’ll use the main sensor anyway. I’d rather have a zoom camera, but you need to upgrade to the significantly pricier ZenFone 4 Pro to get this.
The normal rear camera is very flexible indeed. When you whip the ZenFone 4 out and start shooting instantly, particularly at night, you might find the first photo uses slightly dodgy settings. You’ll see the odd noisy night shot. However, aberrations aside you can get seriously detailed night photos. The phone actually beats the OnePlus 5 here, which doesn’t have OIS.
You can really see the stabilisation working too, as at night people walking around will be reduced to a motion blur. To be clear: this isn’t a bad thing, it’s part of getting good night photos out of a phone.
As you’d hope, daylight photos look great too, with lots of fairly clean detail. The best phones have slightly better, more natural, colour in certain conditions, but the ZenFone 4 has one of the better cameras you’ll find at the price.
It’s quick too, with only a smidge of shutter lag.
The front camera is just solid, with the sort of solid but not mind-blowing 8MP hardware you’d expect at the price. Selfies look OK, but tend to appear a bit weak or washed-out with less than perfect lighting.
Video fans will be pleased to hear capture goes up to 4K resolution, too.
Asus ZenFone 4 verdict
The ZenFone 4 doesn’t seem the phone that will launch the series from the shadows into the pockets of millions of people who think Asus only makes laptops. However, that doesn’t mean it is not a very solid phone in its own right.
A night-shooting-ready camera, good quality build and lots of internal storage make this a totally sound buy. And while Qualcomm deserves the processor props for making the Snapdragon 630 such a good chipset for real-world mid-range performance without compromise, Asus still earns few points for using it.
The design isn’t truly dynamic, and ZenUI is still one of the less charming Android interfaces. However, this is still a phone we’d be happy to use long-term.