Apple unveiled its first and highly anticipated foldable phone in September 2026. Early reviewers praised the iPhone Duo for its premium build, gorgeous 7.6-inch inner screen with a virtually crease-free display, and clever details like the dynamic unfolding effect where the interface smoothly carries over from the front display to the inner one. But just weeks after the first Duo devices started shipping, some customers complained of cracked inner displays, apparently caused by a flaw in the hinge. Apple insisted the defect was confined to a small number of phones, and offered a replacement Duo to affected customers. Thankfully, the issue hasn't turned into a wider problem, but just how durable is the phone's highly engineered hinge?

Cnet decided to put it to the test, building a machine designed for the sole purpose of repeatedly opening and closing single-hinge foldable phones. Since October 23, Cnet has been folding the Duo continuously, occasionally live-streaming the test on YouTube.…