Liquid fuel processing technologies have attracted attention because of the increasing importance of energy and environmental problems. Liquid fuels such as gasoline and diesel are promising hydrogen sources because of their high hydrogen densities, widespread applications and well-constructed infrastructure. Liquid fuels can be used in various applications, such as fuel cells, through liquid fuel processing. Pure hydrogen or natural gas has been used depending on the fuel cell type. However, pure hydrogen and natural gas are unavailable in some applications and areas. Therefore, fuel cell applications can be diversified by using liquid fuels. The liquid fuel delivery, catalytic reforming and reformate cleaning processes have been investigated for producing hydrogen-rich gases. Some kW-class reactors have also been developed for practical applications. This paper will summarize and discuss each liquid fuel processing technology and the kW-class reactors for converting liquid fuels into hydrogen-rich gases in a stable manner. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.