Before we start, the Nexus 6 is made by Motorola for Google (LG made the Nexus 5 and Nexus 4) and it isn't out yet. We haven't seen it yet so although we've reviewed the Sony Xperia Z3 already, we're comparing specs here.
Nexus 6 vs Sony Xperia Z3 comparison: Price and availability
The Nexus 6 won't be available to pre-order in the UK until November and will go on sale before December. UK pricing has yet to be confirmed, although in the US it will cost $649 for the 16GB model and $699 for 64GB. O2 and Vodafone have already confirmed that they will offer the Nexus 6, but not confirmed their pricing.
It looks like it could well be more expensive than the Sony Xperia Z3 which you can pick up for £515 from Clove (Sony's price is £549). That's quite a shock considering the outstanding value of the Nexus 5 at £299 which is, at the time of writing, still on sale on the Google Play store.
Nexus 6 vs Sony Xperia Z3 comparison: Design and build
The Nexus has hit the phablet category with the Nexus 6 and is a huge phone which looks remarkably like the Moto X, but the Z3 is thinner and lighter than its predecessor. Google's phone is 11 mm wider and nearly 13 mm taller which is a significant amount. The Sony Xperia is 7.3 mm and 152 g while the Nexus 6 is 10.1 mm and 184 g.
So the Xperia Z3 is svelte in comparison and comes with the bonus of a dust- and water-resistant design – IP68 which is the highest available on the market. You can completely submerge it in 1.5m of water for up to 30 minutes.
There are four colours of the Z3 on offer: black, white, silver green and copper. Meanwhile, the Nexus 6 will be available in just black and white. Both take a nano-SIM.
Nexus 6 vs Sony Xperia Z3 comparison: Screen
Living up to its name, the Nexus 6 has a 6in screen (5.96in to be precise) and that's why it’s one of the biggest phones around. Sony, on the other hand, has stuck to 5.2in which seems pretty normal in comparison although it's still quite big.
Another big difference is that the Nexus 6 uses a Quad HD resolution (1440 x 2560) which we've seen on the LG G3 and Samsung Galaxy Note 4. That means a super high pixel density of 493ppi.
That outclasses the Xperia Z3 which sticks to Full HD (1080 x 1920) as Sony claims is unnecessary, therefore the Z3 has a – still decent - pixel density of 424ppi. We love Quad HD screens but the size of the Nexus 6 is huge so that fact might be more important. The resolution does have an impact on battery life too.
Google has opted for AMOLED technology like Samsung Galaxy phones while the Sony Xperia Z3 opts for an LCD IPS display.
Nexus 6 vs Sony Xperia Z3 comparison: Processor and memory
Many things on the Z3 are the same as the Z2 and the processor remains the quad-core (Krait 400) Qualcomm Snapdragon 801, although it is clocked higher at 2.5GHz. The RAM also sticks at a very healthy 3 GB. On the GPU side, it has the Adreno 330.
The Nexus 6 has a more up-to-date Qualcomm Snapdragon 805 processor which has newer Krait 450 cores (four of them) and is clocked at a whopping 2.7 GHz. It also has 3GB of RAM but the newer Adreno 440.
It's almost certain that the Nexus 6 will benchmark better than the Z3 but we've reviewed the Z3 and haven't found any problems. The noticeable difference from a user perspective between top-end smartphones is minimal. Also see: What's the fastest smartphone 2014.
Nexus 6 vs Sony Xperia Z3 comparison: Storage
Things are very different in terms of storage as although the Xperia Z3 only comes in 16 GB, it offers a microSD card slot which can accept up to 128 GB.
The Nexus 6, on the other hand, has no expandable storage but you can buy it in either 32- or 64 GB models.
Nexus 6 vs Sony Xperia Z3 comparison: Audio, wireless and extras
It seems audio is becoming an increasingly important area in smartphones and we're pleased about that. Both these phones have front facing stereo speakers which are a nice change from mono rear facing ones. However, the Xperia Z3 also has support for noise cancelling (with the right headphones) and High-Res audio (including DSD files).
Neither phone has a fingerprint scanner or IR blaster but both come with 11ac dual-band Wi-Fi, GPS and NFC. The Nexus 6 does have Bluetooth 4.1 while the Z3 is on version 4.0 and it has Cat 6 4G (300Mbps) while the Z3 has Cat 4 (150Mbps).
One of the selling points of the Nexus 6 is that it comes with vanilla Android which we'll explore below. Sony has a key feature which will launch on the Z3 range in November and that is PS4 Remote Play. It lets owners play PS4 games on the Xperia Z3 over Wi-Fi rather than on the TV screen.
Nexus 6 vs Sony Xperia Z3 comparison: Cameras
The Nexus 6 has a lower resolution camera at 13 Mp but in its favour is optical image stabilisation and a dual-LED flash (ring). Meanwhile, the Xperia Z3 has a 20.7 Mp camera with a dedicated camera/shutter button and improved Steady Shot with Intelligent Active Mode for keeping content smoother – essentially digital image stabilisation. Both can record video in up to 4K (2160p) resolution.
At the front (selfies are mega important these days it seems), the Nexus 6 has a 2 Mp camera while the Xperia Z3's is slightly higher at 2.2 Mp.
Nexus 6 vs Sony Xperia Z3 comparison: Software
As we mentioned already, the Nexus 6 comes with vanilla Android (as Google makes the operating system) and it's one of the two launch devices, along with the Nexus 9, for Android 5.0 Lollipop.
The Xperia Z3 comes pre-installed with Android 4.4 KitKat but Sony has promised an upgrade to Lollipop. That means the main difference here is that Sony loads its own skin or overlay. Its user interface is close to stock Android though and it both stylish and easy to use. PS4 Remote Play and High-Res audio support are the two stand-out features.
We're just comparing specs for now so the Nexus 6 is a huge phone with a Quad HD screen and Android 5.0 Lollipop which looks to be more expensive than the Sony Xperia Z3 which is smaller and features a waterproof design, High-Red audio and PS4 Remote Play.