head to head · open source
Mastodon vs Lemmy
Mastodon has 50,465 GitHub stars, 7,536 forks, 4,525 open issues and last shipped yesterday. Lemmy has 14,659 stars, 973 forks, 129 open issues and last shipped yesterday. Mastodon leads on adoption by 244% (50,465 vs 14,659 stars). Mastodon is written in Ruby under AGPL-3.0; Lemmy is written in Rust under AGPL-3.0. Mastodon has attracted 15% as many forks as stars, Lemmy 7%. Mastodon was the more recently maintained of the two, and both are self-hostable with no licence fee. The two share 2 topic tags (activitypub, fediverse), so they are genuine substitutes rather than adjacent tools.
Two open source projects, one decision. Both are free and self-hostable — the differences are community size, license terms, language stack and release pace.
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Side by side
| Mastodon | Lemmy | |
|---|---|---|
| GitHub stars | ★ 50K | ★ 15K |
| License | AGPL-3.0 | AGPL-3.0 |
| Written in | Ruby | Rust |
| Last push | 2026-11-02 | 2026-11-02 |
| Forks | ⑂ 7.5K | ⑂ 973 |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick Mastodon if
- You weight community size — 50K stars and counting
- You want the AGPL-3.0 license terms
- Your stack matches Ruby
- You value the larger contributor base for long-term maintenance
pick Lemmy if
- You want the Lemmy feature set and don't need the biggest community
- You prefer the AGPL-3.0 license terms
- Your stack matches Rust
- You evaluated both and Lemmy fits your workflow better
About Mastodon
[!NOTE] Want to learn more about Mastodon? Click below to find out more in a video. Mastodon is a free, open source social network server based on ActivityPub where users can follow friends and discover new ones. On Mastodon, users can publish anything they want: links, pictures, text, and video. All Mastodon servers are interoperable as a federated network (users on one server can seamlessly communicate with users from another one, including non Mastodon software that implements ActivityPub!) Navigation Project homepage 🐘 Donate to support development 🎁 View sponsors Blog 📰 Documentation 📚 Official…
read the full Mastodon overview →
About Lemmy
English Español Русский 汉语 漢語 日本語 Lemmy A link aggregator and forum for the fediverse. Join Lemmy · Documentation · Matrix Chat · Report Bug · Request Feature · Releases · Code of Conduct About The Project Lemmy is similar to sites like Reddit, Lobste.rs, or Hacker News: you subscribe to forums you're interested in, post links and discussions, then vote, and comment on them. Behind the scenes, it is very different; anyone can easily run a server, and all these servers are federated (think email), and connected to the same universe, called the Fediverse. For a link aggregator, this means a user registered on one…
read the full Lemmy overview →
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Frequently asked questions
Is Mastodon or Lemmy more popular?
Mastodon has 50,465 GitHub stars and Lemmy has 14,659. Mastodon has the larger community by that measure.
Are Mastodon and Lemmy free?
Both are open source. Mastodon is licensed under AGPL-3.0 and Lemmy under AGPL-3.0. Neither carries a licence fee.
What is the difference between Mastodon and Lemmy?
Mastodon is written in Ruby and Lemmy in Rust. The practical differences are community size, licence terms, language stack and release cadence — all compared in the table above.
Which should I choose, Mastodon or Lemmy?
Choose Mastodon if you want the larger community (50,465 stars) or its AGPL-3.0 licence terms. Choose Lemmy if its feature set, stack or AGPL-3.0 licence fits better. Both are self-hostable.