Mastodon

Mastodon is an open-source, ActivityPub-based microblogging platform that works like Twitter but without the company. Each instance is independently operated and federates with the broader fediverse, meaning a user on one Mastodon server can follow and interact with users on any other compatible server without a centralized intermediary.

Self-hosting a Mastodon instance gives you a social media platform for a community, a company, or a personal audience that you control entirely. Posts, follows, blocks, and content policies all sit on your hardware. You moderate by your own rules rather than those of a platform operator, and your users’ data stays on your infrastructure.

The feature set matches what you would expect from a modern social platform: posts up to 500 characters, media attachments, polls, content warnings, custom emojis, threaded conversations, and a chronological feed. ActivityPub federation means accounts on your instance can follow and be followed by users on Mastodon, Pixelfed, PeerTube, and any other compatible fediverse software.

Mastodon is AGPL-licensed and free to self-host. It is a Ruby on Rails application with a React frontend, and it is not lightweight: a typical production install requires at least 2GB RAM, PostgreSQL, Redis, Elasticsearch for search, and background job workers. The complexity is closer to running GitLab than running a simple PHP application.

Managed hosting options exist for organizations that want a Mastodon instance without the infrastructure overhead.