Yi4. com, also known as Yi Download, is a Chinese website focused on discovering and downloading mobile apps and games. Its catalog covers a broad range of categories, including entertainment, education, business, utilities, social networking, travel, and security, alongside games spanning role-playing, strategy, action, sports, and casual play.

Listings include app or game descriptions, category labels, file sizes, and update dates, with featured, popular, daily, and weekly rankings to help visitors browse current and widely viewed titles. The site also publishes practical tutorials and guides, such as instructions for using app features, managing account settings, and completing game tasks. Curated collections bring together apps or games around themes, including short-video viewing and city-building games.

Yi4. com presents itself as a download resource and information hub rather than the developer of the listed products. Its disclaimer states that games are collected from the internet for personal use and that rights belong to their original creators; it invites rights holders to request removal of infringing material