Apple has unveiled the iPhone 18 Pro, iPhone 18 Pro Max and a foldable model, the iPhone Duo, expanding its premium iPhone lineup into two form factors. The three models differ in form factor, display, camera, battery, authentication method, materials, price and release schedule.

Apple said on Sept. 9 that the biggest difference is the form factor. The iPhone Duo adopts a foldable structure, while the iPhone 18 Pro and Pro Max keep the bar design used in existing iPhones. The iPhone Duo can be used like a standard smartphone when folded and offers a larger screen when unfolded, delivering an experience similar to using an iPhone and an iPad in a single device.

The sizes also differ. When folded, the iPhone Duo measures 117.8 mm tall, 84.1 mm wide and 11.3 mm thick. When unfolded, it is 164.6 mm wide and 5.2 mm thick. It weighs 254 grams. The iPhone 18 Pro measures 150.0 by 71.9 mm, is 8.75 mm thick and weighs 211 grams, while the Pro Max measures 163.4 by 78.0 mm, is 8.75 mm thick and weighs 249 grams.

The display setup also differs significantly. The iPhone Duo has a 5.4-inch outer screen and a 7.6-inch folding display. The iPhone 18 Pro uses a single 6.3-inch display, while the Pro Max uses a single 6.9-inch display. The iPhone Duo's folding display is the first iPhone to feature a nano-texture finish.

◆ Differentiation in camera, battery and software

The iPhone 18 Pro series leads on the camera. The iPhone 18 Pro and Pro Max include a 48-megapixel (48MP) main camera that supports a variable aperture, but the iPhone Duo does not have a variable aperture feature. A telephoto camera is also available only on the Pro models. Dedicated shooting features also differ. The iPhone Duo supports Smart Take, Kid Cue and Duo Preview, while the iPhone 18 Pro offers Smart Focus Tracking, Pro Control and Apple Reference Images. When recording to external storage, it also supports up to 4K 60-frames-per-second ProRes video, a studio-grade four-microphone array, 1080p 30-frames-per-second spatial video, spatial photos, ProRes RAW, Genlock and more.

Battery life also varies by screen. By Apple's measure, the iPhone Duo delivers up to 44 hours of video playback using the outer screen and up to 31 hours using the folding screen. The iPhone 18 Pro offers up to 36 hours, while the Pro Max offers up to 45 hours. The iPhone Duo uses Touch ID for authentication, while the iPhone 18 Pro series uses Face ID. The iPhone Duo does not have an Action button but supports Camera Control.

On software, the iPhone Duo includes features that use its foldable screen. In iOS 27, it allows apps to be used in split-screen, supports a separate view tailored to landscape mode, and offers a standby mode that can be used while partially folded. Later this year, the Apple Pencil USB-C model is also expected to be supported on the iPhone Duo.

◆ Gaps also in materials, price and launch schedule

There are also gaps in materials, colors and pricing. The iPhone 18 Pro series applies an aluminum unibody design, while the iPhone Duo uses titanium. The iPhone 18 Pro comes in four colors: burgundy, glacier, black and silver. The iPhone Duo comes in two colors: Star White and Night Sky.

The price difference is significant. Based on the 256GB model, starting prices are 3.29 million won for the iPhone Duo, 1.99 million won for the iPhone 18 Pro and 2.29 million won for the iPhone 18 Pro Max. The iPhone Duo costs at least 1.3 million won more than the Pro. The release schedules also differ. Pre-orders for the iPhone 18 Pro and Pro Max begin on Sept. 12, with release on Sept. 18. Pre-orders for the iPhone Duo begin on Oct. 16, with release on Oct. 23.

According to IT outlets including 9to5Mac, the iPhone Duo can ultimately be seen as targeting users who prioritize a foldable screen and multitasking, while the iPhone 18 Pro series focuses on users who value the camera and professional video shooting features. Apple has split options within the same premium iPhone lineup depending on form factor and features.