Skip to content
OpenSourceSoftware.ai
SiYuan logo

SiYuan

siyuan-note · Knowledge bases

GitHub stars

46,991
—Awaiting first sync

Awaiting first sync

No measured star history yet

What is SiYuan?

SiYuan is a note-taking and knowledge app for people who want to link ideas at a finer level than whole pages. Every paragraph, heading or list item is a block that can be referenced from anywhere, so notes build into a connected knowledge base. Data stays on your own device, and most features are free, even for commercial use.

SiYuan is a privacy-first personal knowledge management app built around content blocks. Any block can be referenced and linked both ways, documents are edited in Markdown WYSIWYG, and SQL queries, databases and flashcards sit alongside notes. It runs on desktop, Android, iOS and HarmonyOS, or in a browser from a Docker server, with data stored in a workspace you control.

Core capabilities

  • Block-level references and two-way links between any pieces of content.
  • Exports to Markdown, PDF, Word and HTML, with OCR and web clipping.
  • Databases, spaced-repetition flashcards and embedded SQL queries.

Blocks, links and the editor

Every piece of content is a block with its own ID, custom attributes and a siyuan:// link. Blocks can be referenced and embedded in other documents, and backlinks and link graphs show how notes connect. The editor combines Markdown WYSIWYG with list outlines, block zoom-in, maths formulas, charts and diagrams such as flowcharts and Gantt charts, and it can handle very large documents. Templates, JavaScript and CSS snippets, plugins and a community marketplace extend it.

  • Blocks
  • Backlinks
  • Markdown
  • Plugins

Databases, AI and export

Databases show blocks in a table view, with relations and rollups between them. Flashcards use the FSRS spaced-repetition algorithm, and Tesseract OCR reads text from images. AI writing help and question answering connect to the OpenAI API, and an HTTP API and a built-in command-line tool can search, query and export a workspace. Documents export to Markdown with assets, PDF, Word and HTML.

  • Databases
  • Flashcards
  • AI
  • CLI

Install it, and what is paid

Install SiYuan from the App Store, Google Play, F-Droid, the Microsoft Store or GitHub releases, or serve it from the b3log/siyuan Docker image. Data lives in a local workspace folder, and the project warns that syncing it through third-party sync folders can corrupt data. Official cloud sync, and sync to your own S3 or WebDAV storage, are paid membership features. SiYuan is released under the AGPL-3.0 licence.

  • Local-first
  • Docker
  • Mobile apps
  • AGPL-3.0

Where it fits

Use cases

  1. 01

    Connect research notes at the block level

    Write notes in the block editor and reference a single paragraph or heading from another document instead of the whole page. Backlinks on each document show where it is referenced, with filtering and search, and link graphs show connections across the workspace. Embed a SQL query block to collect every block that matches a condition.

  2. 02

    Study with linked notes and flashcards

    Link PDF annotations into your notes so each highlight points back to its source. Turn key blocks into flashcards and review them on a schedule set by the FSRS spaced-repetition algorithm. Tesseract OCR reads text from images you add to your notes.

  3. 03

    Run a private notes server for the browser

    Run the b3log/siyuan Docker image with the serve command, a mounted workspace folder and port 6806, and set a strong lock screen password so nobody else can open your data. OIDC sign-in with Google, Microsoft, GitHub or a custom provider can replace the password. The server edition works in a browser only and cannot export to PDF, HTML or Word.