An image sensor supporting a full resolution mode and a crop mode, the image sensor including: a pixel array including a plurality of pixels configured to generate a pixel signal by sensing an object; an analog-to-digital converter configured to convert the pixel signal into a digital signal and including a plurality of metal lines; a bias generator configured to apply a bias voltage to the plurality of metal lines; and a bias controller including: a first transistor configured to activate all of the plurality of metal lines based on a first control signal; and a second transistor configured to activate a first metal line for the crop mode among the plurality of metal lines based on a second control signal.