The foldable iPhone Duo gives you a bigger screen and bragging rights. Here's what you give up.

• The $1,999 iPhone Duo immediately stands out. Its foldable design also introduces some nifty new iPhone features.
• But there are a few engineering taxes to achieve the foldable design.
• Here are a few areas where the Duo differs from the iPhone 18 Pro in hardware.

Apple’s first-ever foldable smartphone, which ranges between $1,999 and $3,199, gets a 7.6-inch inner display when unfolded, which Apple calls the “largest iPhone display ever.” That’s 50% larger than the screen on the next-gen iPhone 18 Pro.

But even at $700 more than the iPhone 18 Pro Max, the Duo had to put some hardware and capabilities on the cutting-room floor to make room inside the device for new mechanical components.

Sure, early adopters get immediate bragging rights and some cool features that are only available on the foldable phone — but it comes at a cost.

Debating between the iPhone Duo and the iPhone 18 Pro? Here are four of those trade-offs to consider.

A weaker camera system

The camera is perhaps the most notable hardware compromise.

The Duo’s outer, front-facing camera is 12 megapixels, while the iPhone 18 Pro and Pro Max have an 18-megapixel Center Stage camera with autofocus. More importantly, the Pro models have a dedicated telephoto lens for distant subjects; the Duo does not.

It’s not all bad news for photogs. The foldable design includes the 48-megapixel ultrawide lens for wide landscapes and close-up macro shots. That’s nearly the same updated hardware found on the iPhone 18 Pro Max.

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And, Duo’s outer screen serves as a viewfinder when users activate the rear cameras, a first for an iPhone. That lets the subject see the shot as it’s being taken, a feature that, on X, people are calling boyfriend-friendly.

Bottom line: You gain some cool new photo-taking features, but give up some of the top-of-the-line camera tech found in the iPhone 18 Pro lineup.

No Face ID

Do you have a pretty face? iPhone Duo won’t open up to it.

The iPhone Duo is the first premium iPhone in years to swap Face ID for Touch ID. Instead of unlocking the device by looking at it, Duo owners will use a fingerprint sensor built into the side button—or their Apple Watch.

Apple’s iPhone 18 Pro and Pro Max still have Face ID, enabled by the front-facing camera system.

No Action button

Duo isn’t in on the Action button.

The customizable button, placed above the volume controls on the iPhone 15 and later, doesn’t make it onto the Duo.

On the iPhone 18 Pro models, the Action button can be set to silence the phone, open the camera, start a voice memo, trigger a shortcut, or enable focus mode.

The Duo keeps Apple’s camera and volume control buttons.

Less battery life when unfolded

The Duo has two batteries, but its big inner display still draws more power.

Apple says the phone can stream video for up to 26 hours when unfolded, versus 38 hours for the iPhone 18 Pro Max. Even the smaller outer screen offers up to 37 hours of streaming battery life, a little less than the iPhone 18 Pro Max.

Charging will take a bit longer, too. Apple says it takes the Duo 20 minutes to gain 50% of charge from a 60W-capable adapter. It’ll take the iPhone 18 Pro Max 15 minutes to get the same amount of juice.