Only the Pixel is XL in name, but both phones could be considered such. The OnePlus 3 is smaller, but only by 1-2 millimeters in each dimension. When it comes to thickness, there's only a tenth of a millimeter's difference.
The slightly smaller OnePlus is 6-percent lighter.
Both phones have an industry-standard aluminum unibody. The Pixel XL also has a glass accent (read: a breakable portion) on its upper back.
Many of this year's flagships boast a significant water resistance rating, but not these two.
The Pixel has more color options, including blue, which is the most vivid option of the bunch. Otherwise, we're looking at the typical array of neutrals and metallics.
The two displays match in size, which means the OnePlus 3 has a slightly better screen-to-size ratio.
The Pixel lives up to its name by packing a lot more pixels into its screen space. Side by side, it makes a noticeable difference.
Both of these devices opt for AMOLED technology over IPS displays.
Neither of these phones have any equivalent to the 3D Touch display technology that's been in iPhones for a couple of years now. However, Apple hasn't exactly convinced the masses of its utility, so you probably won't miss it.
In the rear camera, the OnePlus 3 wins the megapixel war. But when the pixel counts are already that high (and there are so many other factors that affect camera performance), it's not the most telling spec. The front cameras have a matching 8 megapixels, which should yield some of the sharpest selfies out there.
Camera aperture (rear)
Typically, larger camera apertures on smartphones mean better pictures in low-light conditions. Both of these have a decent f/2.0 aperture. That being said, the Pixel XL has the best low-light photography we've seen from a phone, due to its unique processing algorithms.
Optical image stabilization (OIS)
On paper, Pixel XL's lack of OIS seems like a glaring omission, but again, you won't miss it. In practice, the Pixel's camera is excellent.
Pixel XL's battery has a larger capacity. According to Google, it will get up to 14 hours of internet use or video playback. OnePlus hasn't released official battery life estimates, but it did fare slightly better in our tests: Pixel XL's battery life dropped 11-percent and OnePlus 3's dropped 9-percent in our standard video streaming test.
Nothing proprietary or old-school here. Both of these devices charge via reversible USB-C ports.
Another shared convenience: Both phones rise from the dead quickly, thanks to fast charging.
There aren't any wireless options for charging these two, but the Pixels do ship with generous charging options: USB-C wall adapter, doubled-ended USB-C cord, USB-A to USB-C cord, and a USB-A to USB-C adapter. You shouldn't have any trouble figuring out a way to charge it, regardless of your setup.
The newer Snapdragon 821 in the Pixel XL may be better for gaming and other demanding applications.
The OnePlus 3 has more RAM, but for what it's worth, our experiences with the Pixel and Pixel XL indicate that it's lightning-quick.
The Pixel XL is available with either 32 GB or 128 GB of built-in storage. The OnePlus 3 has an option, an intermediary 64 GB size.
... and you'll have to make do with internal storage on either one. Neither of these phones have microSD slots for expandable storage.
OnePlus 3 is not VR-ready (unless you count low-end Google Cardboard setups), but the Pixel XL is a natural partner for Daydream, Google's new virtual reality headset. Its newer processor and high-resolution display should come in handy for this purpose.
Don't be concerned about connecting to your favorite headphones. So far, only Apple has nixed the headphone jack.
Home button type
The Pixel's home, back and recent apps buttons take up a sliver of onscreen real estate. OnePlus 3 has a physical off-screen home button beneath the display.
The Pixel's fingerprint sensor is on its upper back. On the OnePlus 3, it's incorporated into the home button.
Both phones are NFC (near-field communication) equipped, so Android Pay works on either one.
Pixel and Pixel XL are the first phones to have Google Assistant, an answer to Siri and a grown-up version of Google Now. We talked about the Assistant vs. Siri experience in our Pixel review.
Both phones ship unlocked, but the OnePlus 3 is not compatible with CDMA networks. In the US, that means it's a no-go on Verizon or Sprint.
OnePlus 3 launched four months earlier than the first Google-branded phones.
Starting price (full retail)
Now there's a staggering difference. The Pixel XL costs nearly US$400 more, almost twice the price of the OnePlus 3. Of course, those extra bills get you a superior camera (perhaps the best), VR capability and a beautifully showcased Android experience. Still, the OnePlus 3 is no slouch. It offers several high-end features for a bargain price, as long as network problems and having to put down the entire cost up front (since it isn't available through any carriers) isn't a deal breaker for you.
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