For a successful root canal therapy, determining the length of root canals and limiting the obturation material till that length plays a very vital role. Amidst the existing limitations of the traditional methods to precisely determine the working length, the emergence of Electronic Apex Locators has made it hassle free and given more accuracy to define the apical limit for a clinicianThe apex of the root has specific resistance to electrical current and this is measured using a pair of electrodes typically hooked into the lip and attached to an endodontic file by the apex locatorVarious generations of apex locators have evolved based on changing principles of digitally measuring the flow of electric current across the circuit and various devices signaling this event by a beep, flashing light, digital readout or a buzz.