Hydrogen chloride is a by-product in important processes like the polyurethane production. The currently most efficient electrochemical process for recycling it to chlorine is based on a liquid-phase reactor, utilizing aqueous hydrochloric acid as a feedstock. Recent investigations showed that employing a gas-phase reactor and according novel strategies for product purification leads to significant exergetic savings. This article aims to discuss the efficient electrolysis of gaseous HCl on the reactor level but also on the overall process level in comparison to the current state of the art.