Outline vs Sioyek
Comparing two open source alternatives to Adobe Acrobat . Use the comparison below to decide which one fits your needs.
Outline
The fastest growing-team knowledge base — beautiful, realtime collaborative, feature packed, and markdown compatible Notion and Confluence alternative.
Sioyek
GPL-3.0Cross-platform PDF viewer focused on textbooks and research papers with smart navigation, marks, bookmarks, and bibliography jumping.
Side-by-side comparison
| Outline | Sioyek | |
|---|---|---|
| License | — | GPL-3.0 |
| Self-hostable | Yes | No |
| GitHub Stars | 40,147 | 9,773 |
| Forks | 3,480 | 357 |
| Open Issues | 80 | 321 |
| Last Commit | Aug 14, 2026 | Aug 15, 2026 |
| First Released | May 22, 2016 | Jul 11, 2021 |
| Categories | ||
| Tags | — |
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