Derpibooru

Derpibooru is an imageboard fan site dedicated to hosting and archiving visual fan art created by the My Little Pony: Friendship Is Magic fandom. Launched in June 2012, it is the largest and most popular My Little Pony imageboard. As of January 2026, Derpibooru hosts over 3.3 million images, 520,000 registered users, and 11 million comments.
Similar to established imageboards like 4chan, Derpibooru has a minimalist interface with limited social features. The site allows users to post and comment anonymously and upload My Little Pony fan art, whether previously published on other platforms or original. Derpibooru uses a user-driven tagging system characteristic of folksonomies, which allows for categorization and content searching; it uses a content rating system of seven categories: safe, suggestive, questionable, explicit, semi-grimdark, grimdark, and grotesque.
Derpibooru uses a software called Philomena, which is licensed under the AGPL and written in Elixir, TypeScript, CSS, Rust, and JavaScript. It is the successor to the previously used Rails-based booru-on-rails project.