head to head · open source
Mastodon vs pump.io
Mastodon has 50,465 GitHub stars, 7,536 forks, 4,525 open issues and last shipped yesterday. pump.io has 2,240 stars, 327 forks, 679 open issues and last shipped 9 months ago. Mastodon leads on adoption by 2,153% (50,465 vs 2,240 stars). Mastodon is written in Ruby under AGPL-3.0; pump.io is written in JavaScript under Apache-2.0. Mastodon has attracted 15% as many forks as stars, pump.io 15%. Mastodon was the more recently maintained of the two, and both are self-hostable with no licence fee. The two share 1 topic tag (social-network), 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 | pump.io | |
|---|---|---|
| GitHub stars | ★ 50K | ★ 2.2K |
| License | AGPL-3.0 | Apache-2.0 |
| Written in | Ruby | JavaScript |
| Last push | 2026-11-02 | 2026-02-12 |
| Forks | ⑂ 7.5K | ⑂ 327 |
| 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 pump.io if
- You want the pump.io feature set and don't need the biggest community
- You prefer the Apache-2.0 license terms
- Your stack matches JavaScript
- You evaluated both and pump.io 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 pump.io
pump.io This is pump.io. It's a stream server that does most of what people really want from a social network. What's it for? I post something and my followers see it. That's the rough idea behind the pump. There's an API defined in the API.md file. It uses activitystrea.ms JSON as the main data and command format. You can post almost anything that can be represented with activity streams short or long text, bookmarks, images, video, audio, events, geo checkins. You can follow friends, create lists of people, and so on. The software is useful for at least these scenarios: Activity stream functionality for an…
read the full pump.io overview →
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Frequently asked questions
Is Mastodon or pump.io more popular?
Mastodon has 50,465 GitHub stars and pump.io has 2,240. Mastodon has the larger community by that measure.
Are Mastodon and pump.io free?
Both are open source. Mastodon is licensed under AGPL-3.0 and pump.io under Apache-2.0. Neither carries a licence fee.
What is the difference between Mastodon and pump.io?
Mastodon is written in Ruby and pump.io in JavaScript. 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 pump.io?
Choose Mastodon if you want the larger community (50,465 stars) or its AGPL-3.0 licence terms. Choose pump.io if its feature set, stack or Apache-2.0 licence fits better. Both are self-hostable.