The CR400 is part of the Chinese Standard EMU program designed for a speed of 400 km/h (249 mph). Currently the top speed in service is 350 km/h, while 420 km/h have been reached in trial runs. There are two main variants which are built by different manufacturers, but have compatible technical equipment. The CR400AF “Red Dragon” is being built by CRRC Qingdao Sifang, while the CR400BF “Golden Phoenix” is being built by CRRC Changchun. By 2025, more than 1,100 sets have been built.

The standard variant consists of eight cars, of which four are being powered on all axles by a 650 kW motor each. Letters behind a dash designate sub types, most notably -A for a 16-car variant and -B for a 17-car variant. Other suffixes stand for vehicles which are enabled for automatic train operation, which are resistant against sandstorms and cold climates, or which either have a modernized interior or modernized equipment. There is also a variant for Indonesia that is being designated KCIC400AF.