Loud kei is a subgenre of visual kei that combines the sounds of Western metal with the visual kei movement.

Originating in the mid-2000s, loud kei was inspired by the global spread of nu metal. The subgenre drew influence from bands such as Limp Bizkit, KoRn, Slipknot and DIR EN GREY.

Numerous bands can be classified under the loud kei category, including MUCC, girugamesh, Sadie, lynch., DEATHGAZE, UnsraW, and many others. Additionally, the fourth and fifth generations of Nagoya visual kei are closely associated with this subgenre. Frontrunners like lynch. and DEATHGAZE were joined by junior bands like meth., °C, EAT YOU ALIVE, and gemmik. Even NOCTURNAL BLOODLUST, Dexcore and Deviloof are fit into this category due to their Western metal influences, although they lean much further into deathcore and metalcore.

The amount of visual flair allowed in this genre is flexible. For instance, girugamesh influenced bands to adopt black suits and converse shoes, while Sadie leaned towards a kote-osa aesthetic. Notably, Nocturnal Bloodlust's appearance fluctuates between distinctly visual kei and less visually elaborate styles. It is worth mentioning that loud kei is also associated with non-visual kei hardcore/alternative metal bands, expanding the genre's scope. Artists like Pay Money to my Pain, coldrain, SiM, Crossfaith, and Fear, and loathing in Las Vegas fall within this broader loud kei category. Consequently, some loud kei visual bands have even managed to participate in non-visual kei loud kei events, indicating the subgenre's potential for crossover appeal, although visual kei bands often face preconceptions about their primary genre.

In terms of defining characteristics, loud kei relies heavily on musical influences and sound rather than appearance. The term "暴れ盤" (abare-ban), which describes bands emphasizing fist-pumping and headbanging over hand-waving furi, is closely associated with this style of music.