head to head · open source
Mastodon vs Bluesky
Mastodon has 50,299 GitHub stars, 7,498 forks, 4,525 open issues and last shipped yesterday. Bluesky has 18,295 stars, 2,837 forks, 2,400 open issues and last shipped yesterday. Mastodon leads on adoption by 175% (50,299 vs 18,295 stars). Mastodon is written in Ruby under AGPL-3.0; Bluesky is written in TypeScript under MIT. Mastodon has attracted 15% as many forks as stars, Bluesky 16%. Mastodon 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 | Bluesky | |
|---|---|---|
| GitHub stars | ★ 50K | ★ 18K |
| License | AGPL-3.0 | MIT |
| Written in | Ruby | TypeScript |
| Last push | 2026-09-17 | 2026-09-17 |
| Forks | ⑂ 7.5K | ⑂ 2.8K |
| 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 Bluesky if
- You want the Bluesky feature set and don't need the biggest community
- You prefer the MIT license terms
- Your stack matches TypeScript
- You evaluated both and Bluesky fits your workflow better
About Mastodon
Mastodon is a free, open source, self hosted social network server built on ActivityPub that lets anyone run a microblogging community which interoperates with the wider Fediverse, and it is aimed at individuals, communities, and organisations that want to own their social graph instead of renting it from a platform.
read the full Mastodon overview →
About Bluesky
Bluesky is the open source social application codebase for the Bluesky Social app. It lives in the AT Protocol ecosystem, also called atproto, and it is written in TypeScript as a React Native application. The project provides client code for Web, iOS, and Android, and it builds on open source atproto packages such as @atproto/api, which live in a separate repository.
read the full Bluesky overview →
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Frequently asked questions
Is Mastodon or Bluesky more popular?
Mastodon has 50,299 GitHub stars and Bluesky has 18,295. Mastodon has the larger community by that measure.
Are Mastodon and Bluesky free?
Both are open source. Mastodon is licensed under AGPL-3.0 and Bluesky under MIT. Neither carries a licence fee.
What is the difference between Mastodon and Bluesky?
Mastodon is written in Ruby and Bluesky in TypeScript. 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 Bluesky?
Choose Mastodon if you want the larger community (50,299 stars) or its AGPL-3.0 licence terms. Choose Bluesky if its feature set, stack or MIT licence fits better. Both are self-hostable.