What it does
DiceBear generates avatar images from any text, such as a user name or ID, so every user gets a unique and consistent picture without uploading one. More than 30 styles are available, from initials and pixel art to illustrated faces and abstract shapes, each with options for colours and details. The HTTP API returns SVG, PNG, JPEG or WebP. Free and open source, no key needed.
More information: https://www.dicebear.com/how-to-use/http-api/