The present invention concerns a compact, portable, lightweight, easily transportable, quickly operating wood splitting apparatus, using a knife which cuts a log or piece of wood that is deposed on a platform. This compact and portable wood splitter is actuated by a hydraulic cylinder transmitting a pendulum movement to a knife and onto an upright piece of wood. The apparatus may be attached to a truck box, to a trailer or to a wall by means of a vertical, horizontal, fixed or mobile fixture. The splitter apparatus is compact and portable and it can easily be stored in a car trunk or in a shed.