A foldable Apple product only seems inevitable at this point, but officially, the device, or devices, have only been rumored.

However, with foldable devices being proven to be a viable form factor for smartphones, it seems like a no-brainer that Apple will release a foldable iPhone. But why hasn't the company done it already? In Apple fashion, the company is never early to a new market, and when it does finally jump in, it makes sure its version of an already established product has that Apple shine. In the instance of a foldable smartphone, Apple won't release that device until the dreaded crease problem in the display has completely been solved.
A new report from the Korean blog Yuex1122 states Apple is close to selecting the display supplier for its foldable display, and this supplier will need to "adhere to the technical requirements," which includes impact resistance and crease prevention. Moreover, previous reports indicate Apple is trying to make an extremely thin device that's half as thin as current iPhone models -- so when the device is folded it's the same thickness as a standard iPhone.
These unsurprisingly Apple-fashion stipulations present engineering problems that require breakthrough technology jumps, as previous rumors indicated Apple was struggling with the development of the foldable iPhone due to engineers being unable to implement viable batteries given the footprint of the device. Additionally, BGR reported in February last year that Apple paused the development of its foldable device due to concerns regarding its durability. However, it appears that development has continued.
Current rumors indicate we probably won't see a foldable iPhone until sometime in 2026 or 2027.