To deserve the Ultra moniker, a Sony Xperia needs to be 6 inches or more, and the XA1 Ultra qualifies. It's also a FullHD resolution panel, as anything less would've been too coarse on that diagonal, while more won't make the budget. The resolution is good for 367ppi, perfectly adequate for the class.
Under a microscope, we see a conventional RGB arrangement with an equal number (of equally-sized) subpixels for each primary color.
The XA1 Ultra is very bright at its maximum setting making it past the 600-nit mark, if only just. There's no boost when you enable auto brightness. Blacks are kept in check for what turned out as an excellent contrast, verging on 1600:1. The XA1 Ultra is superior to both last year's XA Ultra and the current smaller XA1 in all three disciplines. Not only that, but the XA1 Ultra outperforms Sony's current flagships as well.
Among potential competitors, few can match the XA1 Ultra's peak brightness, and only AMOLEDs offer better contrast.
Outdoor visibility is great as well, the XA1 Ultra edges out the iPhone 7 Plus in this respect (hit the 'Expand' button above the chart to see it). Even the AMOLED display on the Moto Z Play is no match for the Ultra, though Samsung's own Galaxy A7 (2017) does have the upper hand - not all AMOLEDs are equal.
Hardly a first for a Sony phone, the Xperia XA1 Ultra puts a bluish tint to whites with a grayscale DeltaE of around 9, and an average DeltaE of 6.0, when compared against the sRGB color space.
You can tweak the color reproduction with the RGB sliders in the white balance section of the display settings. You'd need a colorimeter and dedicated software to calibrate it, though. Our trial-and-error attempts led to an average DeltaE of 2.6 with RGB values of 197, 83, 0. That, however, results in a massive dip in maximum brightness - with these white balance settings, the phone only pumped out 380nits. The blue and green pixels are brighter than the red ones and taking away some of the bluish cast lowers the screen's maximum brightness. That's not a glitch as it can be observed with any LCD out there but the dip on the XA1 Ultra after the calibration is more serious than usual.
The Sony Xperia XA1 Ultra comes in single and Dual SIM flavors. Ours is the single SIM version, so we can't comment on how the Dual SIM variety handles the two cards. Cat.6 LTE is supported by the Helio P20's modem for download speeds of up to 300Mbps.
Wi-Fi b/g/n over 2.4GHz and a/n over 5GHz is supported, but not ac. You can stream video wirelessly over Miracast but the XA1 Ultra isn't DLNA certified.
The supported Bluetooth is now v4.2 LE, as opposed to the XA Ultra's 4.1. Bluetooth comes with the audio-focused aptX protocol as well.
NFC is available too, and so is an FM radio receiver.
For positioning, you get GPS and GLONASS, but no BDS or Galileo.
Peripherals can be connected via the USB-C port, but USB 2.0 limits transfer speeds to 480Mbps. There's a good old 3.5mm jack for attaching headphones too.
Just like the small XA1, the Xperia XA1 Ultra relies on the same capacity battery as the model it replaces - that's 2,700mAh. Our skepticism was proven unfounded on the XA1, which posted quite respectable endurance results out of its tiny 2,300mAh cell, so we dived into our testing without worrying all that much.
And that turned out to have been the right attitude as the the Xperia XA1 Ultra's endurance is anything but disappointing. Let's start with what matters most - the tests we carry out with the display on are particularly demanding on the 6-inch Ultra, and 10 hours of video playback is admirable, even if the competition might be capable of more. Almost 12 hours of browsing the web over Wi-Fi is even more praiseworthy.
That's hardly a word to describe the phone's longevity in voice calls, where it couldn't make it to the 13-hour mark. Apparently, Mediatek's modem isn't as efficient in this use case as the competing solutions. But we still think talk time comes a distant second after all the other screen-on activities that you are bound to carry out on your big-screen smartphone.
The less than exciting showing in voice calls means, however, a lower overall endurance rating. Dialing in the numbers from the individual tests into our formula results in an overall endurance rating of 68 hours - not bad, but certainly not class-leading.
Our endurance rating stands for how long a single battery charge will last you if you were to use the smartphone for an hour each of telephony, web browsing, and video playback daily. We've established this usage pattern as they are common day-to-day tasks and it allows our battery results to be comparable across devices. The battery testing procedure is described in detail in case you're interested in the nitty-gritties. You can also check out our complete battery test table, where you can see how all of the smartphones we've tested will compare under your own typical use.
On the software side of things, Sony has also baked in their proprietary Stamina battery saving feature. It has two modes: regular Stamina, and Ultra Stamina. The first disables non-essential features like GPS and vibration, and takes performance down a notch.
Ultra Stamina is for absolutely dire occasions when you don't expect to be able to be near a power outlet for a long period of time. Enable that and it's back to basics where you get a single homescreen with access to the dialer and contacts, text messages, camera, clock - just the basics. Going out of Ultra Stamina requires a restart.