The open-source microblogging platform Mastodon uses emoji designs from Twitter's own open-source Twemoji emoji designs within their default emoji picker. 

As of December 2022, the emoji pickers within two of the most popular Mastodon servers - mastodon.word and mstdn.social - support emojis up to 2019's Emoji 12.0. 

When inserted into a message, emojis will appear in a device's native emoji font (i.e the Apple emoji design set is used via an iPhone or a Macbook).

Additionally, Mastodon allows for a server host to upload a variety of custom shortcode-based emoji designs to the Mastodon instance they manage.

Within the popular mastodon.word server, many of these custom shortcode emojis are reworkings of classic Google blog emoji designs.