A reviewer has put the iPhone Duo's hinge through a long folding endurance run, and her early verdict is that it feels much the same as it did on day one.
According to MacRumors, Joanna Stern built a custom machine that opened and closed her iPhone Duo review unit more than 32,000 times over four nights. The phone was fitted with a case during the run. The rig opened the device flat on each cycle but did not shut it all the way, and Stern used a calibrated push-pull gauge to measure how much force the hinge needed before and after the test.
The gauge readings showed the hinge was actually stiffer after the folds than it had been at the start. Stern had initially wondered whether the mechanism would loosen as the count climbed, but she concluded she could not feel much of a change by hand. In everyday use, she said, she "really couldn't feel a difference," and she described the phone as feeling about the same as when it arrived. The MacRumors write-up does not say whether the crease in the display became more visible, and Stern did not comment on it in the material it cites.
The numbers need some context. Apple has not published hinge test results or a rated lifetime fold count for the iPhone Duo, so there is no official figure to compare with the 32,000 cycles. For reference, Samsung Display has said that the panel used in the Galaxy Z Fold7 passed a 500,000-fold durability test in 2025, which it equates to more than ten years of use for someone folding the phone about 100 times a day. A single review unit folded by a home-built machine is also not a controlled laboratory study, and the result applies to one device.
Stern's findings appear in her video review and in her written review, which covers the phone's strengths and bugs more broadly. MacRumors expects more unofficial folding tests to appear in the coming weeks as the iPhone Duo reaches more reviewers and early buyers, which should give a clearer picture of how the hinge holds up across many units.
The iPhone Duo goes on sale on October 23. Durability has been one of the main questions around Apple's first foldable iPhone, so independent stress tests like this one are likely to be watched closely by prospective buyers.
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