Hinge for doors or windows

A hinge for doors or windows, comprising a hinge-pin defining an axis of rotation, a first hinge element and a second hinge element articulated to one another about said axis via said pin, in which the first hinge element and second hinge element have respective through articulation seats for coupling with said pin and in which said pin has at a first end a head resting against a bottom front end of the first hinge element and a second end substantially flush with a top front end of the second hinge element, the hinge comprising a reinforcement kit comprising an extension element configured as an element detached from the pin that can be applied by shape fit to said second end of the pin, said extension element projecting beyond the top front end of the second hinge element, and a third hinge element configured as element separate from the first and from second hinge elements and connectable to the first hinge element in a pre-set position, the third hinge element having a hole that can be engaged by said extension element of the pin.