head to head · open source
Mastodon vs lemmy-ui
Mastodon has 50,465 GitHub stars, 7,536 forks, 4,525 open issues and last shipped yesterday. lemmy-ui has 1,014 stars, 383 forks, 55 open issues and last shipped yesterday. Mastodon leads on adoption by 4,877% (50,465 vs 1,014 stars). Mastodon is written in Ruby under AGPL-3.0; lemmy-ui is written in CSS under AGPL-3.0. Mastodon has attracted 15% as many forks as stars, lemmy-ui 38%. lemmy-ui was the more recently maintained of the two, and both are self-hostable with no licence fee.
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-ui | |
|---|---|---|
| GitHub stars | ★ 50K | ★ 1.0K |
| License | AGPL-3.0 | AGPL-3.0 |
| Written in | Ruby | CSS |
| Last push | 2026-11-02 | 2026-11-02 |
| Forks | ⑂ 7.5K | ⑂ 383 |
| 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-ui if
- You want the lemmy-ui feature set and don't need the biggest community
- You prefer the AGPL-3.0 license terms
- Your stack matches CSS
- You evaluated both and lemmy-ui 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-ui
Lemmy UI 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 server can subscribe to forums…
read the full lemmy-ui overview →
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Frequently asked questions
Is Mastodon or lemmy-ui more popular?
Mastodon has 50,465 GitHub stars and lemmy-ui has 1,014. Mastodon has the larger community by that measure.
Are Mastodon and lemmy-ui free?
Both are open source. Mastodon is licensed under AGPL-3.0 and lemmy-ui under AGPL-3.0. Neither carries a licence fee.
What is the difference between Mastodon and lemmy-ui?
Mastodon is written in Ruby and lemmy-ui in CSS. 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-ui?
Choose Mastodon if you want the larger community (50,465 stars) or its AGPL-3.0 licence terms. Choose lemmy-ui if its feature set, stack or AGPL-3.0 licence fits better. Both are self-hostable.