Justinsane is a death/thrash metal band from Italy whose self-titled debut (2016) delivers nine tracks of aggressive metal rooted in heavy, thrash, and hard rock traditions. The band formed around the creative vision of Davide Carnevalini and drummer Alessandro Cimaroli, channeling their diverse metal influences into a cohesive heavy sound.

Justire is a heavy metal band from Germany that merges classic European metal sensibilities with a modern production approach. Their French-influenced name hints at a conceptual depth that underpins their powerful metal compositions.

Justonefix is a metal band from Ukraine that creates heavy, atmospheric compositions drawing on post-metal and sludge influences. Their releases including Khachaturian demonstrate an ambitious approach to heavy music that blends classical influences with crushing metal weight.

Juvaliant is a symphonic progressive power metal band from Salzburg, Austria, whose name fuses the city's Latin name Juvavum with the word valiant. Their debut album Inhuman Nature (2010) was released through Limb Music with artwork by Felipe Machado Franco, known for his work with Iced Earth and Ayreon, and addresses weighty themes of war, terror, and discrimination through dramatic orchestral metal.

JvlKvlt is a German depressive post-black metal project whose debut album Worshipping Darkness (2023) channels melancholic atmospherics through layers of tremolo guitar and anguished vocals. The project blends post-rock textures with raw black metal aggression, creating a sonic landscape of bleak introspection.

JWH is a sludge metal band from Vladivostok in Russia's Far East, founded in 2015 and exploring themes of drug addiction and societal decay in their hometown. Their debut album Gidra (2022) blends destructive bass and apocalyptic guitars with barbarian vocals, drawing comparisons to Grief, Conan, and Triptykon.

Jager is a dungeon synth and atmospheric metal project from Saint Petersburg, Russia, creating fantasy-themed compositions that blend neomedieval synth with orchestral and power metal influences. Their album Raevult! (2017) weaves elaborate tales of warring templars and divine conflict through bombastic, Blind Guardian-esque arrangements.

Jager Blaster is a post-stoner rock trio from Besancon, France, blending psychedelic, doom, and stoner influences across three albums since 2014. Their most recent release Introspecta (2019) features nearly 50 minutes of heavy, intense psychedelic stoner rock with immersive atmospherics.

Jaatyakuu, meaning Frostmoon, is a Hungarian one-man raw black metal project driven by strong nostalgia for the music and long winters of the 1990s. Despite being Hungarian, the artist sings in Finnish for its suitability to the genre, with the demo EP Fagyhold (2020) channeling a Burzum Filosofem-inspired raw yet beautiful atmosphere.