Mastodon is a decentralized open source social media platform. Like Discord, Mastodon users create or join their own servers, called instances. Mastodon posts are called Toots and are displayed in chronological order in a feed that is very similar to the layout of Twitter.
The platform's founder, Eugen Rochko, said he developed Mastodon as an alternative to Twitter that focuses on "smaller, tight-knit communities" that are less prone to toxic behavior. The platform is funded by the general public and is ad-free.