iPhone Duo faces early durability concerns

Apple’s first foldable smartphone, the iPhone Duo, went on sale on October 23 in the United States with a starting price of $1,999. Within the first days of availability, some buyers reported durability problems with the inner display, including cracks and bright lines appearing after a limited number of folds.

Owners began reporting damage to the inner display on October 23; some devices showed cracks near the hinge where the screen folds. In some cases, bright lines appeared across the inner display, raising concerns over the device’s ability to withstand repeated opening and closing.

One iPhone Duo buyer in Australia reported that the inner screen broke approximately six hours after purchase. The owner said the phone had been opened fewer than 20 times when an unusual sensation was noticed around the hinge during unfolding, followed by an audible cracking sound and damage along the fold.

Photos shared on Reddit showed inner displays cracking from top to bottom along the hinge less than 24 hours after launch. Some users said their screens cracked during initial setup, and in at least one case an Apple Store exchanged the damaged unit for a new device.

A durability test by YouTuber Zack Nelson, who runs the JerryRigEverything channel, subjected the iPhone Duo to scratch, dust, and bend tests. When dust and sand were applied, particles entered the hinge through multiple ingress points, preventing the phone from closing completely as the magnets could not overcome the debris lodged inside.

In a bend test applying force against the normal folding direction with the screen open, a green line appeared on the inner display. As more pressure was applied, the line spread until the display lost both its image and touch response, and the phone ultimately failed the test. Nelson noted that most foldable phones he has tested over seven years have survived similar procedures.

The outer display of the iPhone Duo, protected by Ceramic Shield 2, scratched at level 7 on the Mohs hardness scale, which is typical for glass. The inner screen scratched at level 2, though its matte nano‑texture coating made many marks less visible, even as underlying damage remained a concern under harsher stress.

Apple had emphasized durability at launch, highlighting a titanium hinge and an in‑house screen protection layer. In the United States, replacing the protective layer on the inner display costs between $19 and $49, depending on whether the owner has AppleCare+. Apple has not issued an official explanation for the failures.