Both phones are substantial phablets, but the iPhone 7 Plus is the more sizable of the two. The OnePlus 3T is about 3-percent shorter and 4-percent narrower than the iPhone, though it is just a whisper thicker.
The iPhone 7 Plus is 17-percent heavier than the OnePlus, which is significant when we're talking about smartphones. That 30 grams isn't going to cause a slipped disc, but there are times when it could make a difference, such as when you're toting your phone during a workout.
Nothing adventurous here. Both of these phones predictably stick to a tried-and-true aluminum unibody build.
Water resistance ratings are becoming increasingly more common in all kinds of mobile technology, but OnePlus has yet to jump on the bandwagon. The iPhone's IP67 rating denotes ingress protection from immersion in up to one meter of water for up to 30 minutes.
OnePlus keeps it simple with two variants: gunmetal (dark gray) and gold. The iPhone 7 Plus is available in matte black, glossy jet black, gold, rose gold or silver.
Even though the iPhone 7 Plus is a larger phone, it has the same 5.5-inch screen size as the OnePlus 3T. OnePlus does a more efficient job of fitting a capacious screen onto the space provided.
The two same-size displays also match in resolution, for a decent density of 401 pixels-per-inch.
We'll be taking a closer look at the OnePlus 3T's display in our upcoming full-length review, but we'll be surprised if it rivals the iPhone's. While the Apple display does not necessarily look impressive on paper, other qualities – like contrast ratio, white balance and color accuracy – make it one of the loveliest we've seen.
The type of display also factors into the viewing experience. OnePlus uses AMOLED technology, while Apple has long stuck with IPS.
3D Touch (pressure-sensitive display)
One feature that is unique to iPhones (so far) is a pressure-sensitive display that enables 3D Touch functionality, a navigational feature that's heavily incorporated into iOS 10. This means that there are more ways to interact with the iPhone's touchscreen, depending on how long/hard you press.
The camera on the OnePlus 3T packs in megapixels like no other. 16 megapixels is more than most rear-facing smartphone cameras have, and a front camera to match is virtually unheard of. Of course, there are other important factors in image quality, but OnePlus handily wins the resolution war, and its selfies should be sharp as a tack.
Camera aperture (rear)
In most cases, a larger camera aperture on a smartphone means better low-light shooting. The smaller the f-stop, the larger the aperture, so the iPhone 7 Plus wins this one. Still, the best way to determine subtle shooting differences is by testing the cameras, so stay tuned for some OnePlus 3T photography samples, which we'll include in our review.
Optical image stabilization
OIS technology prevents camera shakes and jolts from blurring your photography. Both of these phones have it.
Dual-lens camera for optical zoom
The iPhone 7 Plus has a dual-lens rear camera. One of the lenses is a standard 28-millimeter equivalent and the other is a telephoto lens.
The two lenses work seamlessly to enable 2x optical zoom and 10x digital zoom. Combined with the iPhone's software-based Portrait shooting mode, it should offer clearer images of objects shot from a distance as well as enhanced bokeh effects.
The original OnePlus 3 already had a capacious and long-lasting battery, but in this mid-cycle update, it received an additional boost to 3,400 mAh.
OnePlus 3 already beat the iPhone 7 Plus in our standard battery testing (falling only 9-percent in an hour of streaming video over Wi-Fi at a constant luminescence, to the iPhone's 12-percent), so we expect the 3T to win in an endurance contest.
With the OnePlus 3T, a 30-minute fast charge offers enough power for an entire day, and you can even fast charge during intensive phone activities like gaming, GPS navigation, or streaming video (without slowing down the charging speeds). Apple has yet to offer a similar convenience.
On one hand, the iPhone's Apple-made processor duly impressed us with its buttery-smooth operation. On the other, the brand-new fast-clocking Snapdragon 821 processor in the 3T reaches an ever-so-slightly higher speed. The new chip is one of the biggest improvements the 3T makes over its predecessor.
OnePlus 3T doubles the the iPhone 7 Plus' RAM, but in Apple's defense, we've never noticed the type of lagging operation that hints at a memory deficiency.
iPhone 7 Plus has more storage configurations than the 3T does, though if you want that glossy jet black version of the iPhone, you'll have to shell out extra cash for one of the two larger sizes.
Neither of these phones have expandable storage.
Nor are they compatible with any major mobile VR headset.
The OnePlus 3T has a standard audio-out jack for your headphone-plugging pleasure, but the iPhone 7 Plus made waves by omitting it.
Home button type & placement
Both phones have an offscreen home button exactly where you'd expect it to be. On the OnePlus 3T, the home button is a touch-based capacitive one. The iPhone's setup is similar, but the solid-state button just pretends to click, and you can customize the level of haptic feedback.
Both home buttons have fingerprint sensors baked in.
While Google's new Pixel phones get an upgraded virtual assistant, third-party Android phones are still stuck with the old (but quite similar) Google Now. The iPhone, of course, uses Siri.
The OnePlus 3T launches running Android Nougat, or rather a lightly-customized version known as Oxygen OS.
The iPhone runs iOS 10.
If you live in the US and use Verizon or Sprint, you won't be able to use the OnePlus 3T (or at least not with LTE).
The new OnePlus 3T goes on sale, at OnePlus' site, on November 22.
Starting price (full retail)
OnePlus 3T is a fraction of the iPhone's price. Millions of shoppers find plenty to like in iPhones, but if your priority is saving money, it looks like you're going to get a great value in the 3T.
We'll save final judgment about how it stacks up to the iPhone 7 Plus, though, in our full review (stay tuned).