Outline vs SumatraPDF
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.
SumatraPDF
GPL-3.0Lightweight, free PDF, eBook, and comic reader for Windows that launches instantly and stays out of the way; multi-format support with minimal interface.
Side-by-side comparison
| Outline | SumatraPDF | |
|---|---|---|
| License | — | GPL-3.0 |
| Self-hostable | Yes | No |
| GitHub Stars | 40,147 | 17,322 |
| Forks | 3,480 | 2,020 |
| Open Issues | 80 | 135 |
| Last Commit | Aug 14, 2026 | Aug 16, 2026 |
| First Released | May 22, 2016 | Oct 2, 2012 |
| Categories | ||
| Tags | — |
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