A flexible electronic device is used to receive user inputs via flex gestures. The electronic device includes a flexible substrate, a shape sensor configured to determine an axis of bending and a degree of flex of the flexible substrate, and a processor coupled to the shape sensor and configured to determine a flex gesture associated with the axis of bending and the degree of flex, wherein the processor updates an output of the electronic device based on the flex gesture. The output includes display information, user interface elements, and a flex gesture input for a device that is coupled to the electronic device. The flex gestures can be assigned to functions such as moving, zooming, scrolling, cropping, rotating, and selection to manipulate content associated with the flexible electronic device.