head to head · open source
Mastodon vs Smithereen
Mastodon has 50,465 GitHub stars, 7,536 forks, 4,525 open issues and last shipped yesterday. Smithereen has 548 stars, 37 forks, 44 open issues and last shipped yesterday. Mastodon leads on adoption by 9,109% (50,465 vs 548 stars). Mastodon is written in Ruby under AGPL-3.0; Smithereen is written in Java under Unlicense. Mastodon has attracted 15% as many forks as stars, Smithereen 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 | Smithereen | |
|---|---|---|
| GitHub stars | ★ 50K | ★ 548 |
| License | AGPL-3.0 | Unlicense |
| Written in | Ruby | Java |
| Last push | 2026-11-02 | 2026-11-02 |
| Forks | ⑂ 7.5K | ⑂ 37 |
| 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 Smithereen if
- You want the Smithereen feature set and don't need the biggest community
- You prefer the Unlicense license terms
- Your stack matches Java
- You evaluated both and Smithereen 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 Smithereen
Federated, ActivityPub compatible social network with friends, walls, and groups. If you have any questions or feedback, there's a Telegram chat you can join. Building/installation Running directly on your server Recommended: use the installation script 1. Install JRE or JDK 21 or newer from your distribution's package manager, here, here or here 2. Install MySQL. Note: on Debian, apt get install mysql server would instead install MariaDB, which is known to be incompatible with Smithereen. 3. Download a prebuilt bundle for your CPU architecture from the latest release to your server and unpack it somewhere 4…
read the full Smithereen overview →
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Frequently asked questions
Is Mastodon or Smithereen more popular?
Mastodon has 50,465 GitHub stars and Smithereen has 548. Mastodon has the larger community by that measure.
Are Mastodon and Smithereen free?
Both are open source. Mastodon is licensed under AGPL-3.0 and Smithereen under Unlicense. Neither carries a licence fee.
What is the difference between Mastodon and Smithereen?
Mastodon is written in Ruby and Smithereen in Java. 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 Smithereen?
Choose Mastodon if you want the larger community (50,465 stars) or its AGPL-3.0 licence terms. Choose Smithereen if its feature set, stack or Unlicense licence fits better. Both are self-hostable.