Why you can trust TechRadar We spend hours testing every product or service we review, so you can be sure you’re buying the best. Find out more about how we test.
- There's a 4K screen - that's a huge deal!
- Super fast fingerprint scanner on the home button
- You can play PlayStation games on your phone... well, sort of
The Sony Xperia Z5 Premium's headline feature is that 4K display. It looks gorgeous at 5.5 inches and an incredible 2160 x 3840 pixel resolution.
If you do the math, that works out to 806 pixels per inch, that's massive, and it makes the quality of some of the content you watch on the screen the best it can be.
I was impressed with the Samsung Galaxy S6's display last year, and to put that into perspective that phone only has a 571ppi display.
I've been watching a lot of 4K video on the Sony Xperia Z5 Premium to assess the quality of the screen and it truly is stunning. However, I also have to admit that in practical terms it doesn't offer that much more than the competition.
The real problem here is that even though it is a 4K phone, most of the time you're using a 1080p display. To be able to gain access to the 4K resolution you need to be watching high-quality video or photos within Sony's Photos or Video apps.
But it is disappointing that Sony has claimed this is a 4K resolution, when most of the time you're only watching it in normal HD.
When watching higher-quality videos on the Samsung Galaxy S6, LG G4 and Sony Xperia Z5 Premium, it's very difficult to discern the difference in quality. Yes, I know it's 4K – but 2K at these screen sizes looks just as good, and isn't such a major drain on the battery.
It's nice to know that you have the highest pixel density going on a phone, but you can't help but feel that Sony did this because it wanted the distinction of offering a 4K display under its belt, rather than because it wanted users to enjoy very marginally superior images.
If you're after lots of pixels, the display on the Galaxy S6 looks quite similar – it's not as large, but then there's the Galaxy S6 Edge+ if you think bigger is better.
That said, the Xperia Z5 Premium's screen is gorgeously bright, and I've found myself disappointed whenever I had to turn the brightness down – it looks relatively dull at anything below 60%, and it's a true shame when I have to turn it down to save on battery.
Viewing angles are excellent, even though Sony isn't using its Triluminous screen tech in the Xperia Z5 Premium.
Overall the Sony Xperia Z5 Premium's display is superb – it's just not quite as breathtaking as I'd have liked it to be, and it doesn't stand out enough from the 2K competition to make it worth the extra power it uses.
Fingerprint sensor
Sony has included a fingerprint sensor on its Xperia Z phones for the first time with the 5 series, and on the Xperia Z5 Premium this is integrated into the power button on the right-hand edge of the phone.
This is an interesting placement that no other manufacturer seems to be doing right now. The metal button sits flush with the side of the phone, and has a nice feel to it – it must be a pain for left-handed users though.
I found it easy to set up the fingerprint sensor, and it's very responsive – perhaps too much so sometimes.
I recommend registering all the fingerprints of your favoured hand, because if you tap the power button to check the time this can sometimes be interpreted as a failed attempt to unlock the phone – and three of those means you need to use your PIN on the front screen.
I also find it quite irritating to unlock the phone on a desk when TouchID on the iPhone is just there on the front waiting.
PS4 Remote Play
Everyone seems to forget that Sony phones now include PS4 Remote Play – and it's really one of the biggest selling points of the Xperia range. I love it – it means you can wirelessly connect your DualShock 4 controller to your phone, and use it as a screen for your PlayStation 4 games.
If someone else wants to watch TV, and you want to get on with Star Wars: Battlefront but you don't want to leave the room, you can sit on the sofa and do both.
The problem is that at the moment your phone has to be on the same wireless network as the PlayStation console, so you can't use the feature at a friend's house, for example.
I found the connection on the Xperia Z5 Premium just as good as with the other Sony products I'd tested. I don't have the strongest internet, so I don't always get the full experience – but when it's working it's fantastic.
I much prefer the PS4 Remote Play experience on the Xperia Z4 Tablet with its 2K large display, but it's much easier to play fiddly games on the Xperia Z5 Premium's generous screen than on the Xperia Z5 or Xperia Z5 Compact.
I can't wait for Sony to go the whole hog and enable you to play games wherever you are. Playing Rocket League on my commute might well be all my dreams come true.
Waterproofing
Like the other phones in the Xperia Z5 series the Z5 Premium is IP68-rated, meaning it's dust-proof, and water-resistant up to 1.5 meters for up to 30 minutes.
This means you can use your phone in the rain, or take it into the bathroom, without worrying about it getting damaged – you can even run it under a tap if it gets dirty and not have to worry about the internals getting frazzled.
No other phone manufacturer is offering this technology in such a way right now, and it's easy to overlook how useful it can be.
It's something you don't really appreciate until you lose it – I'm always conscious when I switch to a non-Sony phone that I'll have to be more careful around water.
