The Sony Xperia Compact Z3 was a great small-sized phone back in its day. Released in 2014, the small 4.6in smartphone brought flagship specs to a small form-factor device. It has since been discontinued, but luckily, those who were a fan of the small device will be pleased to know that the XZ1 Compact is a newer, better and more readily available device.

If you're still interested in knowing about the older Xperia Z3 Compact, continue reading our review, below.

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Sony Xperia Z3 Compact review: Design

Measuring a relatively chunky 8.6mm thick, the 4.6in Z3 Compact has a much more angular design than its big brother, the Xperia Z3. It still has Sony's new nylon corners to help it survive a short drop, but the frame is now made of a slightly pearlescent, rubberised plastic and there's an extra rim running along the top and bottom of the phone that joins onto its two tempered glass front and rear panels.

Like the Z3, the glass back can feel a little slippery at times, but this becomes less of a problem when the phone's size makes it so much easier to grasp in one hand. I'm a big fan of the new frame, too, as it not only looks great and is comfortable to hold, but it also adds a bit of personality to help separate it from other mid-sized handsets.

Sony Xperia Z3 Compact review: Display

The Z3 Compact's 4.6in screen doesn't have the Full HD resolution of its big brother, but its 1,280x720 display provides more than enough definition for a screen of this size. With a pixel density of 319ppi (pixels-per-inch), this means the Z3 Compact sits just below the iPhone 6 in terms picture clarity, and I couldn't see any signs of jagged text or pixellated app icons in Sony's modified version of Android 4.4.4.

The screen's colour accuracy was also excellent, as the colour calibrator showed it was displaying 96.7 per cent of the sRGB colour gamut. This is exactly what I'd expect to see from a good IPS panel and the screen's high brightness of 482.58cd/m2 helped colours pack plenty of punch. It's a shame it couldn't quite match Sony's claim of 600cd/m2 like the Z3, but it's still significantly brighter than other mini handsets such as the Samsung Galaxy S5 Mini and HTC One Mini 2 and I had no problem using the phone outside either.

^ The Xperia Z3 Compact is available in white, black, red and turquoise

A lower brightness has a few advantages, though, namely that the screen produces deeper, inkier-looking blacks. I measured a black level of 0.37cd/m2 on the Z3 Compact, which was noticeably darker than the Z3. It's a long way off from the totally pitch blacks you'll find on the S5 Mini's AMOLED display, for instance, but it's still pretty good for an IPS panel.

Contrast was great, too, measuring 1,280:1. This is actually a fraction higher than the Z3, but both phones showed a high level of detail in all of my test images. The Z3 Compact's viewing angles were also superb, as we could see the screen clearly from even the most acute angles, such as when I put it down on my desk or looked at it from the side.

Sony Xperia Z3 Compact review: Performance

Underneath the screen is where the Z3 Compact really stands out from other mini handsets, though, as Sony's chosen to use the same 2.5GHz quad-core Qualcomm Snapdragon 801 processor in both the Z3 and Z3 Compact. This is unusual for this kind of handset, as it essentially puts the Z3 Compact on a level playing field with both the Z3 and its main competition, such as the Samsung Galaxy S5 and LG G3, making it by far one of the most powerful phones you can buy for under £350.

This makes the Z3 Compact all the more impressive, as its day-to-day performance blows almost everything else in its price range out of the water. In the SunSpider JavaScript benchmark, for instance, only the Nexus 5 was able to beat the Z3 Compact's score of 826ms. Other handsets, such as the HTC One Mini 2, Samsung Galaxy S5 Mini and even the current model of the Motorola Moto X all finished around the 1,100ms mark.

As a result, web browsing felt much smoother on the Z3 Compact and I was able to zoom in and pan round image-laden desktop pages with only minimal signs of stutter. Likewise, Android 4.4.4 has never felt more responsive on a mid-tier phone. Menus and the app tray zipped along with no signs of lag whatsoever, and Sony's shimmering, twirling ribbon background looks great as you swipe between home screens.

A top of the range processor also means top quality graphics performance, and the Z3 Compact maxed out both of the 3DMark Ice Storm and Ice Storm Extreme tests just like the Z3. Ice Storm Unlimited posed no threat to it either, as it scored an impressive 18,230 (or 77.7fps), so even the most demanding games and apps should run at a full 60fps. Games that automatically tailor their graphics should always look their best, too, as the Z3 Compact was able to run Epic Citadel at an average of 54.4fps on Ultra High quality settings.

^ The GCM10 Game Control Mount will be available separately, turning your Xperia Z3 Compact into a portable screen for your PS4

This would be an excellent set of scores for any flagship phone, but the Z3 Compact's gaming potential goes one step further with its PS4 Remote Play support, which can be accessed through the normal PlayStation app that comes pre-installed on every handset. It's an ingenious tool, as it essentially lets you use the phone as a remote screen for your PS4 over your home network, turning your PS4 into a portable games console. I'm not sure the Z3 Compact's small screen will be quite as suited to this as the larger Z3.

Sony Xperia Z3 Compact review: Android 6.0 Marshmallow

The Xperia Z3 Compact still ships with Android 4.4 Kitkat out of the box, but an over the air update for Android 6.0 Marshmallow is now available for both Xperia Z3 and Z3 Compact owners. Little has changed between the two updates, though, as Sony's kept its interface largely the same in terms of appearance.

The main differences include notifications on the lock screen, which you can interact with or dismiss with a simple touch or swipe. You can also swipe directly to the phone dialler and camera from the bottom right and left corners of the lock screen. The Notifications bar is customisable as well, and I was pleased to see Sony supporting multiple user accounts as well, as not all phone manufacturers have chosen to implement this feature.

Android 6 also includes much-improved control over app permissions and superior standby battery life.

Sony Xperia Z3 Compact review: Battery life

With such powerful hardware under its belt, I was worried the Z3 Compact's battery life wouldn't be able to replicate the same exceptional standards I saw on the Z3, but it actually went one better. In our continuous video playback test, the Z3 Compact's 2,600mAh battery lasted an unprecedented 20 hours with the screen set to half brightness. This is the longest battery life I've seen from any phone I've ever tested, and is a full 90 minutes longer than the Z3 - when compared to every other handset released in 2014, including those running iOS and Windows Phone, the Z3 Compact takes a noticeable lead. With so much staying power at its disposal, lighter users should easily reach Sony's claimed estimate of two days battery life before needing to recharge it.

This is phenomenal for a mid-range handset, but the phone should last even longer if you enable one of its three power saving profiles. Low-battery mode disables mobile data, Bluetooth, Wi-Fi and auto-sync, while Stamina restricts hardware performance as well. Ultra Stamina mode, meanwhile, only lets you use a few basic functions, such as calls and texts.

With 16GB of storage, there's plenty of space for your photos and video files on the Z3 Compact, but there's also a microSD card slot which can take cards up to 128GB if you need more room. It's hidden underneath one of the plastic flaps that help keep the phone waterproof up to a depth of 1.5m. Moving files around is easy, too, thanks to Sony's File Commander app.

Sony Xperia Z3 Compact review: Camera

On the back is Sony's 20.7-megapixel 1/2.3in Exmor RS camera sensor. It's the same sensor that's in the Z3 and you can turn the camera on simply by holding down the dedicated shutter button on the side of the phone. As with previous Xperia handsets, the Superior Auto mode locks pictures to 8-megapixels, so you'll need to switch to Manual to take higher resolution shots.

On Superior Auto mode, my outdoors photos actually looked much crisper than those I took on the Z3 at the same time. There was more detail at the edge of each frame and there was slightly less noise present in background buildings. Colours looked a fraction richer, too, and the level of exposure felt more balanced overall. It's surprisingly given the cameras are supposedly identical.

^ The Xperia Z3 Compact's camera outperforms any other handset we've seen at this price

^ There was plenty of detail present in all areas of the frame and colours looked rich and vibrant

There was less of a difference when I switched Manual mode, but I was still very pleased with the quality of the photos. There was more noise present toward the outer edges, but there are plenty of options to help you adjust the picture, including ISO and white balance options as well as a slider bar for exposure compensation. The Z3 Compact also has an HDR mode and different scene options, but the latter becomes greyed out once you choose to take pictures at 20.7-megapixels.

^ When we switched to Manual mode, the amount of noise around the edge of the frame increased, but the quality was no worse than what I saw on the Z3

^ Despite the increase in noise, colours still looked rich and natural in Manual mode and the camera handled the low mid-afternoon sunshine very well

Sony Xperia Z3 Compact review: Conclusion

Even a few years on, the Sony Xperia Z3 Compact is still a very capable mid-range smartphone. It was arguably the first 'mini' phone that truly lived up to the idea of delivering a flagship experience inside a smaller chassis. Even today its fast processor and incredible battery life make it a pleasure to use. But, since it has been discontinued, you'll struggle to find it new. If you're looking for a brand new device with modern-day specifications, get the newer XZ1 Compact, instead.