September 9, 2026, 7:06 pm | Read time: 7 minutes

Tonight, the tech world turned its attention to Cupertino: Apple unveiled the new iPhone 18 Pro generation at its September event. iPhone 18 Pro and iPhone 18 Pro Max emerged as sure candidates for the presentation. Additionally, Apple finally revealed its first foldable after many rumors–the iPhone Duo. We have gathered all the important information, and TECHBOOK was live on site in Cupertino.

Compact Case in Passport Format

When closed, the iPhone Duo resembles a passport and is similar to the Samsung Galaxy Z Fold 8. With a display diagonal of 5.4 inches, the exterior is roughly in the size class of the iPhone 12 mini and iPhone 13 mini, but it’s wider than it is tall. Despite having more screen size, it easily fits into a pocket.

Some people have already tried the device. They report that despite its unusual design, it feels good in the hand and is easy to store. The hinge also gives a high-quality and stable impression.

Large Inner Display in iPad Format

When unfolded, a second display appears, offering a diagonal of 7.6 inches. The screen is thus 50 percent larger than the iPhone 18 Pro Max and 90 percent larger than the iPhone 18 Pro. Due to the different aspect ratio, the actually usable screen area is significantly larger.

The inner display has an aspect ratio of 4:3, reminiscent of an iPad. This gives applications more space for additional controls, sidebars, or the simultaneous display of multiple contents.

At the same time, the wide screen is better suited for videos than the almost square inner displays of many other foldables. Movies and series in 16:9 format can run with comparatively small black bars.

Thinner than the iPhone Air

Particularly striking is the device’s thinness. When opened, it is thinner than the iPhone Air, making it the thinnest device from Apple ever.

When folded, the case thickness doubles. The foldable iPhone is therefore significantly thicker when closed than a regular iPhone.

Display Crease–Yes or No?

A known issue with foldable smartphones is the visible and tangible crease in the middle of the inner display. Manufacturers have now found ways to minimize the crease. Apple also put great effort into a complex folding mechanism that distributes the stress from folding as evenly as possible. Early testers have positively rated both the workmanship and the hinge.

Dual Camera Without Telephoto Lens

Users will have to make compromises with the cameras. A dual camera with a main sensor of 48 megapixels and an ultra-wide-angle camera also with 48 megapixels is included. There’s also a Center Stage front camera with 12 megapixels (slightly weaker than the iPhone Pro and Pro Max), ultra-stabilized video, dual recording, and a FaceTime camera for the first time under the display.

However, there is no dedicated telephoto lens with two times zoom. For enlarged shots, only a two times digital telephoto zoom or a crop from the main sensor is available. A true optical zoom is not possible.

The omission is likely due to the limited space in the thin case. Telephoto cameras, especially systems with folded periscope optics, take up comparatively much space. With a starting price well over 2,000 euros, the reduced camera equipment could still draw criticism.

Touch ID Returns to the iPhone

Apple is also taking an unusual approach with biometric unlocking. Instead of Face ID, the foldable iPhone features a Touch ID sensor. This is located in the side power button, similar to certain iPad models.

The fingerprint sensor requires less space than the components needed for Face ID. This allows Apple to reduce the display bezels and especially the thickness of the case.

The foldable iPhone is thus the first new Apple flagship model in years to revert to Touch ID. Whether users see this as a step back or a welcome return of Touch ID will likely depend on personal preferences.

Performance at Pro Level

In terms of storage, Apple is expected to remain at the level of its Pro models. Four options are available for internal storage:

• 256 GB
• 512 GB
• 1 TB
• 2 TB

Like the iPhone 18 Pro and 18 Pro Max, the iPhone Duo also gets the new high-end A20 Pro chip with the dual 16-core Neural Engine. It is Apple’s first smartphone chip based on TSMC’s 2-nanometer architecture. This chip not only delivers more power but is also significantly more energy-efficient. It is specifically designed to handle the AI demands of Apple Intelligence.

Dual Battery System for More Power

For the iPhone Duo, Apple uses the first dual battery system, facilitated by the space-saving eSIM design. On the inner display, the Duo can play videos continuously for up to 31 hours, and up to 44 hours on the outer display.

Apps Adapt Dynamically

Apple has been preparing developers for more flexible display sizes and aspect ratios for some time. Applications should no longer be designed exclusively for fixed device classes and rigid orientations. Instead, their interfaces must adapt to different dimensions.

This is particularly important for a foldable iPhone. An app must switch from the small outer display to the large inner screen as seamlessly as possible when unfolded. Content should not just be enlarged but should make meaningful use of the additional space.

Apple not only stretches existing iPhone interfaces but also creates its own layouts for the larger screen. Also clever: If a button is supposed to move to the center when unfolded, the display immediately recognizes this and slightly shifts the area, making it easier to press.

Colors of the iPhone Duo

The new foldable comes in two color variants, officially called “Starlight White” and “Night Sky,” which are white and dark blue:

More on the topic

"Ultra" Model How the First Foldable iPhone Performs in Early Tests

Samsung Takes a New Path Hands-On With the Galaxy Z Fold 8

Production Apparently Faces Problems

Foxconn reportedly began a test production of the iPhone Duo in spring 2026. Such a step usually occurs before transitioning to mass production and serves to check manufacturing processes and identify potential errors.

Mass production was initially supposed to start in June but was then postponed to the end of July. Even this date apparently could not be fully met. Difficulties with the hinge and flexible display, component shortages, and high production costs are said to have affected the schedule.

Currently, “Nikkei Asia” reports that only a few hundred units are produced each day.

Also interesting: What new devices does Apple have in the pipeline?

Dates and Prices for the Most Expensive iPhone Ever

Earlier estimates ranged from 2,000 to 2,500 U.S. dollars. During the 2026 keynote, Apple officially announced the prices, including for the European market:

For Germany, the following prices apply:

• 256 GB: from 2,299 euros (95.79 euros/month)
• 512 GB: from 2,549 euros (106.21 euros/month)
• 1 TB: from 3,049 euros (127.04 euros/month)
• 2 TB: from 3,799 euros (158.29 euros/month)

The iPhone Duo is thus the most expensive smartphone Apple has ever offered. Interested parties can pre-order it from October 16 at 2 p.m., and it will be available from October 23.