A pixel array and an image sensor are provided. The image sensor includes a substrate, a pixel array of pixels, each pixel including a pixel circuit and a pixel conversion device. The pixel circuit is formed in a pixel area corresponding to the pixel in the substrate. The pixel conversion device is arranged on the substrate to vertically overlap the pixel circuit. The pixel circuit includes a floating diffusion node, a reset switching device, and an amplifier including a load device and a plurality of switching devices, the load device being arranged in the pixel area.