Sony Xperia Z5 vs Samsung Galaxy S6: What's the best Android phone?

Sony's Xperia Z5 has just gone on sale in the UK. Before you splash out, we find out how it compares to the current king of the Android phone market, the Samsung Galaxy S6. Read our Z5 vs S6 comparison - now updated with benchmarking results.

Note that this comparison is based largely on specifications. You can learn more in-depth information about each phone in our Xperia Z5 review and Galaxy S6 review.

Sony Xperia Z5 vs Samsung Galaxy S6: Price & UK availability

While the Sony Xperia Z5 has only recently gone on sale, and the black UK version still commands £599 (Amazon; the Gold and Green versions will be available on Amazon on 22 October at the official RRP of £549), Samsung's Galaxy S6 has now been on sale six months and is available much more cheaply at £376 SIM-free (Amazon). If you're looking to buy either phone on a contract this price difference will be largely irrelevant. Also see: Sony Xperia Z5 UK release date, price and specs.

It's worth pointing out that you might find better value with the slightly slimmed down but also cheaper Sony Xperia Z5 Compact. To see how it differs from the standard Sony Xperia Z5 and Xperia Z5 premium read our comparison of the Xperia Z5 series.

Samsung Galaxy S6

Sony Xperia Z5 vs Samsung Galaxy S6: Design & build

The Samsung Galaxy S6 and Sony Xperia Z5 are premium-looking phones with metal frames and stylish glass front and rear covers, with the Xperia Z5 slightly more boxy in its appearance. While the Z5 uses frosted glass at the rear, the S6 has a mirror finish. It's available in black, white, green and gold, and the S6 in black, white, gold and blue. Also see: Best phones 2015.

Both smartphones have fingerprint scanners, but the Xperia Z5's implementation is arguably more user-friendly, built into the power button on the device's right edge and falling naturally under the thumb as you pick up the phone. Samsung's fingerprint scanner is found in the Home button at the front of the device, and a double-tap of it instantly launches the camera app - a nice touch.

While Samsung also includes a heart-rate scanner on the device's rear, which pairs with the S Health app to keep tabs on your health and fitness, Sony has included some extras that could potentially turn the heads of long-term Samsung fans. Also see: Best Android phones 2015.

The Galaxy S6 sits at the top of our best smartphones chart, and we think it's a brilliant Android phone. But Samsung has made some compromises in its design, which has infuriated fans. The S6, unlike its predecessor, is not waterproof, it doesn't feature a removable battery, and there's no support for microSD.

The Xperia Z5's battery isn't removable either (although it is higher in capacity at 2900mAh vs 2550mAh and likely to last longer given the lower-resolution screen - Sony says up to two days for most users), but Sony has included support for IP68 dust- and waterproof protection, plus a microSD slot that can accept memory cards up to 200GB in capacity.

The Samsung Galaxy S6 is smaller, thinner and ligher than the Sony Xperia Z5, measuring 143.4x70.5x6.8mm and weighing 138g against the Z5's 72x146x7.3mm, 154g. This doesn't surprise us, given the aforementioned higher-capacity battery in the Z5, plus the larger screen. Also see: Best MiFi 2016.

You're unlikely to notice the difference in size between the 5.1in panel on the S6 and the 5.2in panel on the Z5, but what you will notice is the difference in both resolution and appearance. Sony fits a full-HD (1080x1920) Triluminos IPS screen, while Samsung plumps for a Quad-HD (1440x2560) SuperAMOLED panel with a super-high pixel pitch of 532ppi. (If you want a Quad-HD Sony you'll need to look to the more expensive Sony Xperia Z5 Premium.)

Given the differing screen technologies, you will notice a difference in more than just clarity. SuperAMOLED is thinner and more energy efficient, with typically oversaturated colours; IPS is known for its realistic colours and excellent viewing angles. Which you like best is very much down to personal preference. See all phone reviews.

Sony Xperia Z5

Sony Xperia Z5 vs Samsung Galaxy S6: Hardware & performance

Sony has fitted the Xperia Z5 with the Qualcomm Snapdragon 810 chip and Adreno 430 GPU originally intended to go in the Samsung Galaxy S6, but overheating concerns led Samsung to instead opt for one of its own chips, the Exynos 7420 (the Z5 doesn't overheat in normal use as did the Xperia Z3+). Both are 64-bit octa-core processors and immensely powerful, especially when backed with 3GB of RAM as they are here - in real-world use you will find neither phone slow.

In our performance benchmarks the Samsung Galaxy S6 outran the Sony Xperia Z5, recording 4438 points in Geekbench 3.0 against the Z5's 4212, 462ms in SunSpider against the Z5's 644ms, and 30- and 14fps in the onscreen elements of T-Rex and Manhattan. The Z5 managed a faster 53- and 26fps in GFXBench, but has far fewer pixels to power. Also see: What's the fastest phone 2015?

For storage both phones come with 32GB built-in, but while the S6 is also available in 64- and 128GB variants the Z5 accepts microSD cards up to 200GB.

As we mentioned earlier the Sony Xperia Z5 has the higher-capacity- and likely longer-lasting battery, but only the Samsung Galaxy S6 supports wireless charging. Quick Charge is possible with either phone. Also see: 100 funny things to ask S Voice

Samsung Galaxy S6

Sony Xperia Z5 vs Samsung Galaxy S6: Connectivity & extras

Whether you buy your smartphone from Samsung or Sony you'll need a nano-SIM to take advantage of its 4G cellular connectivity. For Wi-Fi they each support dual-band 802.11ac with MIMO, and you'll get Bluetooth 4.1, NFC and GPS.

The Sony Xperia Z5 will offer the better audio experience. While the S6 has a single speaker, found on the device's bottom edge, the Z5 has S-Force front-facing speakers and support for hi-res audio. It also supports PS4 Remote Play.

Of these two Android Lollipop smartphones (both will be upgraded to Marshmallow in time), the Xperia Z5 has the plainer implementation of Android. However, in fairness to Samsung it has stripped back TouchWiz and the user experience is much more friendly here than it was with the S5.

Sony Xperia Z5

Sony Xperia Z5 vs Samsung Galaxy S6: Cameras

On paper the Sony Xperia Z5 blows away the Samsung Galaxy S6 on the photography front, but more megapixels doesn't necessarily translate to better performance, and in our tests (prior to the Z5's release) we found the Galaxy S6 to be one of the best camera phones on the market. It really is an awesome camera. Also see: Best camera phones 2015.

The Xperia Z5 comes with 1/2.3in 23Mp Sony Exmor RS rear- and 5Mp 25mm wide-angle lens front cameras. The primary camera can focus in 0.03 seconds (and more often than not it did in our tests), and features 5x Clear Image and 8x digital zoom, a Pulse LED flash, a 24mm wide-angle G Lens, SteadyShot stabilisation, and can operate up to ISO 12800 (3200 for video). This camera is capable of 4K video recording, too.

By comparison the Samsung Galaxy S6 matches the 5Mp front camera, but at the rear it has a 16Mp camera with smart optical image stabilisation and an f/1.9 wide-angle lens that allows for better shots in low light. The S6's camera is always on in the background, so it will spring into action and be ready to shoot in just 0.7 seconds. Plus an IR sensor can automatically detect and adjust white balance.

The Z5 camera is very good but while DxO ranks it as the best in the world, we wouldn't go quite so far. It's up there with the best and we'll be updating our best camera phone group test with a detailed comparison with rivals soon.

Read next: Best new phones coming in 2015/2016.

Follow Marie Brewis on Twitter.

Sony Xperia Z5: Specs

  • Android 5.1 Lollipop
  • 5.2in Triluminos Display IPS (1080x1920, 424ppi)
  • 2.2GHz Octa-Core Qualcomm Snapdragon 810 CPU
  • Adreno 430 GPU
  • 3GB RAM
  • 32GB internal storage
  • microSD slot (up to 200GB)
  • 23Mp rear camera AF with LED Flash
  • 5Mp front camera
  • Video recording at up to 2160p
  • Wi-Fi up tp 11.ac
  • Bluetooth
  • NFC
  • 4G LTE Cat 6
  • Nano-SIM
  • 2900mAh battery
  • Dust and waterproof (IP68)
  • 72x146x7.3mm
  • 154g
  • Android 5.1 Lollipop
  • 5.2in Triluminos Display IPS (1080x1920, 424ppi)
  • 2.2GHz Octa-Core Qualcomm Snapdragon 810 CPU
  • Adreno 430 GPU
  • 3GB RAM
  • 32GB internal storage
  • microSD slot (up to 200GB)
  • 23Mp rear camera AF with LED Flash
  • 5Mp front camera
  • Video recording at up to 2160p
  • Wi-Fi up tp 11.ac
  • Bluetooth
  • NFC
  • 4G LTE Cat 6
  • Nano-SIM
  • 2900mAh battery
  • Dust and waterproof (IP68)
  • 72x146x7.3mm
  • 154g

OUR VERDICT

If you're buying these phones SIM-free then the Samsung Galaxy S6 wins, more than £200 cheaper, faster, with a higher-resolution screen and an excellent camera. If you're buying on a contract, though, the Galaxy just got some real competition - the Xperia Z5 has the microSD support and waterproofing protection Samsung fans are crying out for, and with better battery life and more impressive audio quality to boot. Of course, it also has an outstanding camera and offers plenty of raw processing power, especially in graphics. Our SIM-free money is on the Galaxy S6, but if you're buying on a contract then you will find it difficult to fault the Xperia Z5.