The Sony Xperia Z1 Compact packs the same blisteringly powerful quad-core processor, 4G LTE connectivity and 20-megapixel camera as Sony's top-end Xperia Z1. It has a 4.3-inch display, rather than the palm-stretching 5 inches of its brother, making it the most technologically advanced small Android phone you can get.

While the iPhone 5S provides great performance in a compact size, if you want a top-end phone running Android, you'll need to pocket a phone pushing 5 inches or more. We've seen miniature flagships before from the likes of Samsung and HTC. While the Galaxy S4 Mini and HTC One Mini both bear the names of their elitist brethren, however, both models actually come with considerably watered down specs that won't keep hardcore tech fans happy. The Z1 Compact provides cutting-edge tech without forcing you to have a phone so big you can camp under it.

The Sony Xperia Z1 Compact is due to go on sale in the UK and wider Europe in the middle of February for £449, SIM-free from Sony's online store or free on contracts starting at £29 per month from Phones 4U. Sony so far has no plans to bring it to the US.

Design and build quality

Size aside, the Z1 Compact is almost identical to its bigger brother. It has the same all-glass front and back, with the one-piece aluminium band running around the edge. The same chunky power button pokes out of the side and there's a dedicated camera shutter button below.

It's a gorgeous, sleek design that feels every bit as luxurious as it looks when you pick it up. The metal band curves gently at the edges to meet the screen and there's no unpleasant creaking or flexing when you squeeze it. All in all, it feels like an extremely well put together piece of kit. One thing to bear in mind though; with glass panels on the front and back, the Z1 Compact is susceptible to scratches and scuffs. If you want it to stay looking its best, try not to carry it in the same pocket as your keys.

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The Compact is available in a host of bright colors, including hot pink and a rather vibrant lime green. They might not be to everyone's tastes, but they certainly stand out from the crowd. If colors aren't your thing, you can pick it up in white or black instead.

Like the Z1, the Compact is waterproof to a depth of one metre for up to 30 minutes. Not only can you drop it in the bath or spill a drink on it without worrying, you can dive into the chilly sea and happily snap away at the jellyfish. The camera shutter button means you don't need to tap on the display to take a photo -- which won't be able to register your finger underwater. The charging port and SIM slot are covered with rubberised flaps, but thankfully the headphone jack has been made waterproof, so you don't need to undo a flap every time you want to plug your headphones in.

The Z1 Compact has slimmer bezels than the standard Z1, which helps maximise screen size, without bulging out the phone's body. The Compact is a full 17mm shorter than the regular Z1 and 9mm narrower. Those might not seem like huge numbers, but the size difference is immediately noticeable when you hold the two phones together. I found the Compact much easier to hold in one hand and it shouldn't embarrassingly bulge out of your jeans pocket.

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It comes with 16GB of internal storage as standard, but you can find a microSD card slot under a waterproof flap, allowing you to expand the space to fit all your music and photos.

Display

The Compact packs a 720p display, which is a step down from the Full HD of its brother. Don't let that fool you into thinking it's not a great screen though, because it really is. For one, the smaller screen size means it doesn't need as many pixels to remain sharp. Indeed, it has a pixel density of 340 pixels per inch, which is a step above the 326ppi of the iPhone 5 -- and you'd have to be in a pretty foul mood to call that low resolution.

Side by side, I couldn't really tell much difference in sharpness and clarity against the Compact and the Full HD Z1 for everyday tasks. Icon edges are extremely crisp and small text on Web pages was easily readable. You don't have the same screen real estate of course, so if you mostly want your phone for watching high definition video then the 5-inch Z1 would probably still be a better option. Rest assured though that the Compact's display is more than good enough to do justice to Netflix movies.

The Compact's screen is very bright, countering most of the glare from our office lights. I can say with certainty that it's easy to read in the rain-soaked streets of London, although I sadly can't say how it will fare under the bright California sun. Its IPS display technology helps its deliver bold colours -- without looking over-saturated -- and it has great viewing angles too.

Software and processor

The Compact runs the last but one version of Android, known as 4.3 Jelly Bean. At the time of writing, Sony wasn't able to give a firm word on when the Compact, or indeed the full-sized Z1 would see an update to 4.4 KitKat. It's a little disappointing not to see the latest software on board a new top-end phone, but 4.3 is at least recent enough for it to be acceptable.

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The software looks identical to the interface on the Z1. You can have up to seven home-screens to pop apps and widgets on, with four customisable app icons along the bottom for quick access. The app menu can be arranged into alphabetical order, a custom order or your most used apps, making it easy to find the tool you want when you have half the Android store installed on your phone. Sony uses its own image and video galleries which I'm not keen on as the folder system is much more awkward to use than the stock Android version. The rest of the interface is simple enough though and won't challenge existing Android users.

Unlike other miniaturised versions of top end phones, the Z1 Compact comes with the same supercharged processor as its larger sibling, rather than a weaker, cheaper chip. It's a 2.2GHz quad-core Qualcomm Snapdragon 800 processor, backed up by 2GB of RAM, that delivers a massive serving of power.

It rivalled the Z1 on benchmark tests -- as well as similar phones like the LG G2 -- and was easily capable of playing demanding games like Dead Trigger 2, Asphalt 8 and GT Racing 2. I also found simply swiping around the Android interface and switching between open apps in the multitasking carousel to be satisfyingly swift, with zero noticeable lag. In power terms, there's no question that the Z1 Compact is every bit as powerful as its larger sibling.