A JHH file is an archive used by Tetris Online Poland (TOP), an online Tetris game where you can play others around the world. It contains multiple game data files that are referenced by the game for various aspects of gameplay, such as sounds, skins, music, and images.

You will only encounter JHH files if you have TOP installed on your computer and are navigating game data resource files in the installation directory of the game. The files are compressed to save space and are not meant to be opened. However, users looking to modify TOP gameplay can unpack JHH files with the SjeJHH tool.