What 32,000 Folds Did to the iPhone Duo's Hinge - MacRumors

Over the course of the testing, Stern said she thought it might be feeling looser as the number of folds increased, but her final conclusion was that she couldn't feel much of a change. A calibrated push-pull gauge used to take readings before and after the Duo fold test showed the hinge was actually stiffer than before.

But in everyday use, I really couldn't feel a difference. So, after 32,000 folds, it felt pretty much the same as day one, which is pretty darn impressive.

Stern didn't comment on whether the fold test caused the crease to be more visible, which can happen over time with other foldable devices. Her testing was done with a case on, and while the machine opened the Duo flat, it didn't close it all the way each time.

iPhone Duo Review: Putting Apple's Folding Phone Through Hell Joanna Stern

Samsung's foldable displays undergo official testing, and in 2025, the display used for the Galaxy Z Fold7 passed a 500,000-fold durability test. Samsung Display says that translates to over 10 years for average users folding their device about 100 times a day, or over six years for users who fold it more than 200 times daily.

Until Apple shares information on display and hinge durability, Stern's test is all we have to go on. It's unlikely to be the last unofficial folding stress test that we see over the next few weeks.

The full details on Stern's machine, including how it was built, can be found in her YouTube video, and she has more information in her review writeup.

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Joanna Stern’s review is very good overall. 32,000 folds is roughly a year of normal usage.

32,000 folds in 4 nights:

What does that have to do with anything? The plastic screen is brand new and supple. This test only proved that it survived the torture for 4 nights. Worthless

That's a fair point. Plastic does degrade over time. I guess this tests does tell us that hinge system is pretty durable. Though like you, I'd like to see some long term testing with that screen considering it is plastic and how well that coating holds up over the years. Early adopters will be our guinea pigs.;)