Grab either device and you’ll be met with some notable new design traits, namely their squared appearance (more so over the previous generation), created primarily by the frame surrounding each phone’s edge.
With the Z5 Compact this comes as a continuous piece with cutouts for hardware controls including a shutter key and a flap on its left side. The full size Z5 features these same traits, but features small line breaks with more heavily rounded corners, making for a softer, more organic aesthetic over its smaller sibling.
Whilst the Compact is smaller, it’s also marginally thicker than the full-sized Z5 (8.9mm versus 7.3mm), but that’s partly in an effort to offer a comparable level of battery longevity and what’s more it’s understandably the lighter of the two Z5s (138 grams as opposed to 154 grams).
Both phones benefit from advancements in Sony’s waterproofing technology, meaning you only have to worry about a single flap, designed to protect the nanoSIM and microSD card slot. Charging now takes place via an exposed microUSB port, which significantly ups the convenience factor too.
Sony’s taken a different tact with the glasswork on both Xperias this time around, with a black bezel surrounding the display irrespective of which colourway you opt for and both also boast an arguably more attractive frosted glass back over their respective predecessors (which is also more resistant to scuffs and fingerprints).
Speaking of colours, both devices come in Graphite Black and white, but the Compact is available in punchier, brighter pastel shades such as coral and yellow too. Meanwhile the standard Z5 can be had in more conservative tones like gold and dark green if that’s more your style.
The biggest differences beyond size with these two handsets are their screens. As with last year’s Xperias, both sport the same respective screen sizes and resolutions for their class: a 4.6-inch, 720p HD display for the Compact and a 5.2-inch Full HD panel for the Z5.
Side by side you can expect balanced and consistent colour, contrast and strong overall brightness from both panels; whilst individual pixels are perceptible from either handset, the tighter 428ppi of the Z5’s screen gives it greater fidelity overall.
Whichever handset you favour though, you’re in for a fantastic viewing experience and for the pixel junkies wanting more, there’s always the Z5 Premium.
Sony’s made small, considered changes to the overlay that it dresses Android 5.1 Lollipop with. Both handsets pack near-identical user experiences, so the difference falls more to the fact that there’s more screen real estate on offer from the larger Z5 and features like floating apps may be better utilised on that handset as a result.
Overall this version of Sony’s UI feels closer to stock Android than any previous incarnation. That said you can still find unique customisation options, a number of pre-installed third party applications, like Dropbox and AVG (which can be uninstalled if you don’t want them) and distinct first-party apps and experiences that you won’t get on any other smartphone (namely both device’s PlayStation integration) outside of Sony’s family.
If it’s raw horsepower you’re after, Sony has bestowed both of the Z5 twins with one of the most powerful chipsets on the market, the Qualcomm Snapdragon 810. This 64-bit octa-core processor proves its worth time and again, with incredibly responsive performance for everything from general UI interaction to multi-tasking and intensive 3D gaming.
The Compact sports 2GB of RAM, whilst the Z5 3GB, but that’s primarily down to extra pixels the larger phone needs to be able to push around. Extended 3D gaming or other intensive applications do cause these phones to heat up, but this doesn’t appear detrimental to performance.
Interestingly the Z5 features a smaller 2900mAh battery (whilst the new Compact packs a 2700mAh cell) than its predecessor, but both phones offer better overall longevity when compared to Sony’s previous-generation Xperias.
The standard Z5 will see you through around a day and a half of normal use on a single charge, whilst the Compact can manage a full two days. The lack of wireless charging is a small sting, but both phones also offer support for Qualcomm’s QuickCharge 2.0 technology which goes some way to ease the disparity with offerings from Samsung’s camp, for example.
Sony hasn’t touched the sensor size of its cameras since the Xperia Z1 line, so the Z5 and Z5 Compact mark a notable shift in the maximum resolution of the company’s smartphone cameras, both boasting 23-megapixel rear sensors and 5.1-megapixel front-facing cameras.
Looking at the raw imaging output, both phones offer great all-round performance, with a particular talent for macros, great handling in high contrast and low light scenarios and impressively smooth video recording (which reaches right up to 4K).
Most of the improvements beyond that are software based, with an enhanced Superior Auto mode that still lets you adjust colour temperature and exposure in real-time as well as shoot at the camera’s full resolution without having to jump into manual.
Check out our Xperia Z5 vs Xperia Z5 Compact vs Xperia Z3/Z3+ camera comparison for more info.
The differences are small but clear between Sony’s latest handsets. The standard Z5 offers the bigger, better screen and the slicker overall appearance, whilst the squatter Z5 Compact is the phone to pick if great battery life is at the top of your list.
Whichever handset you favour you can expect impressive performance, great imaging capabilities, plenty of room for storage and the benefits waterproofing. The Z5 Compact is the more affordable of the two at £429, whilst the Z5 can be had direct from Sony for £549.
Read next: Xperia Z5 camera supertest and review