head to head · open source
Outline vs Zotero
Outline has 40,590 GitHub stars, 3,562 forks, 78 open issues and last shipped yesterday. Zotero has 15,308 stars, 1,120 forks, 1,600 open issues and last shipped yesterday. Outline leads on adoption by 165% (40,590 vs 15,308 stars). Outline is written in TypeScript under a custom or non-standard licence; Zotero is written in JavaScript under a custom or non-standard licence. Outline has attracted 9% as many forks as stars, Zotero 7%. Zotero 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
| Outline | Zotero | |
|---|---|---|
| GitHub stars | ★ 41K | ★ 15K |
| License | Custom / other | Custom / other |
| Written in | TypeScript | JavaScript |
| Last push | 2026-09-17 | 2026-09-17 |
| Forks | ⑂ 3.6K | ⑂ 1.1K |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick Outline if
- You weight community size — 41K stars and counting
- You want the Custom / other license terms
- Your stack matches TypeScript
- You value the larger contributor base for long-term maintenance
pick Zotero if
- You want the Zotero feature set and don't need the biggest community
- You prefer the Custom / other license terms
- Your stack matches JavaScript
- You evaluated both and Zotero fits your workflow better
About Outline
Outline is an open source knowledge base application built with React and Node.js, designed for teams needing a fast, collaborative documentation platform. It runs as a self hosted service or via a hosted option at getoutline.com, and its source code powers the public instance along with all supporting services. The project lives in the JavaScript/TypeScript ecosystem and uses MobX for state management.
read the full Outline overview →
About Zotero
Zotero is a free tool for research sources. It lives in the JavaScript application ecosystem and is listed under Productivity & Utilities / Note Taking & Knowledge Management. The provided GitHub metadata reports 15,272 stars, 1,117 forks, 1,600 open issues, 0 contributors, a repository age of 0 years, and a last push timestamp of 2026 09 14T16:40:51Z. The homepage is https://www.zotero.org, and no topics are listed. The license field is NOASSERTION.
read the full Zotero overview →
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Frequently asked questions
Is Outline or Zotero more popular?
Outline has 40,590 GitHub stars and Zotero has 15,308. Outline has the larger community by that measure.
Are Outline and Zotero free?
Neither Outline nor Zotero declares a licence in this registry, so check each project's own repository before relying on either for a commercial use. Both are free to self-host.
What is the difference between Outline and Zotero?
Outline is written in TypeScript and Zotero 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, Outline or Zotero?
Choose Outline if you want the larger community (40,590 stars) or its Custom / other licence terms. Choose Zotero if its feature set, stack or Custom / other licence fits better. Both are self-hostable.