Foldable smartphone
A foldable smartphone (also called a foldable phone or simply foldable) is a smartphone with a folding form factor. While folding designs have been used previously in clamshell or "flip phone" models, the term "foldable" now generally refers to a newer style featuring flexible displays in which the display itself folds. Some variants of the concept instead use multiple touchscreen panels connected by a hinge.
Various structural layouts exist in this category. Devices may fold horizontally on a vertical hinge into a wider, tablet-like form, which typically use an inward-folding booklet-style design with a smaller screen on the outside cover allowing interaction without opening the device. Some early devices, such as the Huawei Mate X, used an outward-folding design in which a single display would wrap around to the back of the device when folded. A more recent category is the emergence of tri-folds, which contain two hinges rather than one and allowing for ever greater display sizes on the interior. Foldable smartphones in a clamshell form factor (folding vertically on a horizontal hinge) have also been produced.
Concepts for such devices date back as early as 2008, although the first commercially available folding smartphones with OLED displays began to appear at the end of 2018, namely the Royole FlexPai, while the first mass-market foldable was the Samsung Galaxy Fold released in 2019. The first generation of commercially released foldable smartphones faced concerns over durability and their high prices, and were largely regarded as a gimmick. However, improvements in physical technology have led to improved durability and usability of foldables, with book-style foldables and tri-folds in particular being seen as practical alternatives to the standard "slate" form factor as of 2026. In 2023, only around 1% of worldwide smartphone ownership were foldable smartphones.