Avatars.io is an avatar hosting service. It is designed for integration with mobile apps and websites. Developers can use the Avatars.io to host the avatars their users assign themselves. After they are uploaded, the avatars can be retrieved at different sizes. Avatars.io is fully compatible with Gravatars and social media sites like Twitter, Instagram, and Facebook. The entirety of Avatars.io functionality is a RESTful API that exposes avatar upload and retrieval. It returns JSON-formatted data.