SiYuan
SiYuan is a free, open-source notes app for Android. Open-source knowledge workspace for humans and AI agents. It has 480 GitHub stars and is released under the AGPL-3.0-only license, and you can install it from F-Droid and Google Play.
- Android
- Java
- Notes & to-do
- Actively maintained
About SiYuan
SiYuan is an open-source, privacy-first, self-hosted knowledge workspace where humans and AI agents work together. Features Most features are free, even for commercial use. Content block Block-level reference and two-way links Custom attributes SQL query embed Protocol siyuan:// Editor Block-style Markdown WYSIWYG List outline Block zoom-in Block horizontal layout Million-word large document editing Mathematical formulas, charts, flowcharts, Gantt charts, timing charts, staffs, etc.
Privacy and F-Droid
F-Droid builds SiYuan from its published source code and flags anti-features such as ads, tracking or reliance on non-free services.
No anti-features flagged on the latest F-Droid build.
Screenshots
Screenshots from the app's F-Droid listing.
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What is SiYuan?
SiYuan is a free, open-source notes app for Android. Open-source knowledge workspace for humans and AI agents. It has 480 GitHub stars and is released under the AGPL-3.0-only license, and you can install it from F-Droid and Google Play.
Is SiYuan free and open source?
Yes. SiYuan's source code is public on GitHub under the AGPL-3.0-only license, which is OSI-approved or FSF-free. F-Droid, which builds it from source, flags no anti-features such as ads or tracking on its latest build.
How do I install SiYuan?
You can install SiYuan from F-Droid (package org.b3log.siyuan) and from Google Play; the links are on this page.
Is SiYuan still maintained?
The repository's most recent commit was on Oct 7, 2026. Its F-Droid listing was last updated on Oct 1, 2026. appsgit only lists apps whose repository had a commit in the last six months.