A hinge has a first bracket, a first pivot pin, a second pivot pin, a second bracket and a positioning and limiting assembly. The first pivot pin is on the first bracket. The second pivot pin is mounted rotatably on the first pivot pin and has a mounting recess. The second bracket is mounted pivotally on the second pivot pin. The positioning and limiting assembly is mounted in the mounting recess in the second pivot pin and has a seat, a positioning disk and limiting disk. The seat is mounted in the mounting recess. The positioning disk is mounted to the first pivot pin and detachably engage the seat. The limiting disk is mounted to the first pivot pin and selectively abuts seat. The positioning and limiting assembly in the mounting recess makes the hinge compact and easily apply to portable devices such as cell phones and digital cameras.