The log splitter is a machine or equipment used to separate firewood from logs of softwood or hardwood that are pre-cut into sections (circles), usually with a chainsaw or saw bench. Most log splitters consist of a hydraulic or electric rod and piston assembly, and these are usually graded with the tons of force they can generate. The higher the ratio of force, the greater the thickness or length of fissile projectiles. The log splitter consists of all four main hydraulic components.

Most log splitter models for home use have a rating of around 10 tons, but professional hydraulic models can apply 30 tons or more of force. There are also manual log splitters that use mechanical lever to force logs through a sharpened blade assembly; and screw or "corkscrew" types driven directly from the PTO shaft of an agricultural tractor where the splitter is mounted on a three-point linkage.

A simple log splitter can be powered by an electric motor driving a hydraulic pump, or a petrol or diesel engine with or without a tractor. Non-electric versions can be used remotely where the splitter can be moved to the location of the cut wood source. The split logs can then be loaded onto trucks, trailers or bulk bags.

Regardless of the power source, a log splitter uses a hydraulic piston to pass the billet through a stationary blade, or a rotating cone-shaped screw mandrel that pulls the billet over a wedge. Some models have attachments that prevent split logs from falling to the ground, allowing the operator to quickly reposition the logs for a second pass in the log splitter. Some cone or screw splitters are mounted on steel platforms mounted on a 3-point linkage that allows the slab to be repeatedly cut into small pieces without lifting the wood down and over.