Key Takeaways
- SiYuan is free and open-source under AGPL-3.0, developed by the B3log organization (Yunnan Liandi Technology Co., Ltd.)
- Core organizational unit is the block — a paragraph, heading, list item, or table cell — each individually referenceable, embeddable, and linkable
- Supports bidirectional links, a backlink panel, and an interactive link graph for visualizing connections between notes
- Notes and blocks are stored fully on your own device by default; no account or internet connection is required for local use
- Optional AI features — writing assistance, Q&A chat, and agent-style workflows — connect to an LLM provider you configure (OpenAI-compatible APIs, including self-hosted backends)
- Extensible through a plugin system plus JavaScript/CSS snippets
- Available on Windows, macOS, Linux, Android, iOS, and HarmonyOS, with a self-hostable server/web (Docker) mode for browser access
- GitHub repository shows roughly 46,400 stars as of September 2026
📍 In One Sentence
SiYuan is a free, open-source, self-hosted knowledge-management app that stores every note as a linkable block on your own device, with a paid tier only for optional encrypted cloud sync.
💬 In Plain Terms
Instead of a cloud note app that stores everything on someone else's server, SiYuan keeps your notes on your own computer or phone by default. You can link individual paragraphs to each other (not just whole pages), extend the app with plugins, and optionally plug in an AI provider for writing help — but none of that requires paying anything unless you want SiYuan's own cloud sync.
What Is SiYuan?
SiYuan is a self-hosted, block-based personal knowledge-management application — a note-taking system where the fundamental unit is not the page, but the individual block (a paragraph, heading, list item, code block, or table cell). Its own site describes it as a "privacy-first personal knowledge management system, supporting fine-grained block-level reference and Markdown WYSIWYG." Because every block has its own identity, you can reference, embed, or link to any block from anywhere else in your notes, not just link between whole documents.
- Core function: a block-based editor and knowledge base that stores content locally by default, with optional self-hosted or paid cloud sync
- Editing model: Markdown WYSIWYG with 20+ block-level and 10+ inline element types, plus math formulas, flowcharts, and web clipping
- Linking model: bidirectional links between blocks, a backlink panel, and an interactive graph view
- Database views: table-style database blocks with rollup fields for structured data inside your notes
- AI integration: writing assistance and Q&A chat that connects to an LLM provider you configure (SiYuan's documentation names OpenAI-compatible API support)
- Developer: B3log (Yunnan Liandi Technology Co., Ltd.), an organization that also maintains other open-source tools such as the Solo blogging engine and Vditor editor
- Canonical repository: github.com/siyuan-note/siyuan
SiYuan's Project History and Version Milestones
SiYuan is developed by the B3log organization, a China-based open-source group that has maintained several developer and content tools since the mid-2010s. The project has shipped continuously on GitHub, and its release history (visible on the GitHub Releases page) shows frequent point releases — the changelog for the current stable line alone documents dozens of alpha, beta, and stable builds.
What Can You Do With SiYuan?
SiYuan's feature set centers on block-level note organization, with AI, database, and spaced-repetition features layered on top. Here is what each part actually does, per SiYuan's own documentation and GitHub README.
- Block-based editing — every paragraph, heading, list item, and table cell is an individually addressable block you can reference, embed, or move independently of the rest of the document
- Bidirectional links and graph view — link blocks to each other, see incoming links in a backlink panel, and visualize connections across your whole knowledge base in an interactive graph
- Database blocks — build table-style databases inside your notes, with rollup fields for aggregating data from linked blocks
- Spaced repetition — a built-in flashcard system using the FSRS (Free Spaced Repetition Scheduler) algorithm for active-recall learning
- AI writing assistant and Q&A chat — connect an LLM provider (OpenAI-compatible APIs, including self-hosted backends) for drafting help and asking questions against your notes
- Plugin ecosystem — extend SiYuan with community and official plugins, plus JavaScript/CSS snippets for custom styling and behavior
- Large-document handling — SiYuan's documentation describes support for very large documents through dynamic loading, rather than loading an entire note into memory at once
- Multi-device use — a self-hostable server/web mode (via Docker) lets you access your notes from a browser or run SiYuan as a personal server, separate from the paid official cloud sync
Usage Examples: Three Ways to Use SiYuan
These are concrete workflows built from SiYuan's documented features above, not hypothetical use cases.
Build a fully offline personal knowledge base
Install SiYuan on desktop, create a notebook, and start writing in the block editor. Link related blocks to each other as you go, and use the backlink panel to rediscover connections later. Everything is stored locally by default — no account or internet connection is required once the app is installed.
Turn your notes into flashcards for spaced repetition
Select blocks you want to memorize and add them to a flashcard deck. SiYuan's built-in FSRS-based spaced-repetition system schedules review sessions for you, the same underlying approach used by dedicated flashcard apps like Anki, but working directly against blocks already in your notes.
Connect an AI provider for Q&A over your notes
In Settings, add an OpenAI-compatible API endpoint and key — this can be a cloud provider or a self-hosted backend such as Ollama. Once configured, you can use SiYuan's AI chat to ask questions or get writing assistance grounded in your own note content, without SiYuan itself ever storing your notes off-device.
Download SiYuan for Desktop and Mobile
SiYuan is available on Windows, macOS, Linux, Android, iOS, and HarmonyOS. Links below are from the official download page and GitHub releases — always verify against those pages directly, since build URLs and version numbers change between releases.
Platform | Download |
|---|---|
| Windows | Installer (x86_64) or Microsoft Store |
| macOS (Apple Silicon) | siyuan-3.8.4-mac-arm64.dmg |
| macOS (Intel) | siyuan-3.8.4-mac.dmg |
| Linux | AppImage, .deb, or .rpm (x86_64 and ARM64) |
| Android | Direct APK or Google Play |
| iOS | App Store |
SiYuan also ships an official Docker image for self-hosting a server/web instance, which lets you run SiYuan on a home server or VPS and access your notes from any browser — a self-hosted alternative to the paid official cloud sync. Actual usability on mobile depends on your device; there is no published hardware minimum beyond running a supported OS.
SiYuan Pricing: Is SiYuan Really Free?
Yes, for local use — the core app is free forever, with no feature gate on block editing, linking, plugins, or local AI connections. SiYuan's paid tiers exist specifically for its official cloud services, per b3log.org/siyuan/en/pricing.html.
Free
- Price:
- $0
- What it adds:
- Full local app: block editing, linking, database blocks, plugins, spaced repetition, and self-configured AI connections — no time limit
PRO
- Price:
- $64 one-time (list $96)
- What it adds:
- Third-party sync/backup integration, including Amazon S3 and WebDAV
Subscription
- Price:
- $148 one-time / lifetime (list $296)
- What it adds:
- Everything in PRO, plus official end-to-end-encrypted cloud sync with 8GB storage, a cloud inbox, and automatic backup
Pricing above reflects the lifetime/one-time figures published on SiYuan's own pricing page at the time of this review — verify current pricing and any promotional discounts directly on b3log.org/siyuan/en/pricing.html, since prices and offers can change. Using your own AI provider (OpenAI, a self-hosted model, etc.) is billed separately by that provider, not by SiYuan.
SiYuan vs. Obsidian
SiYuan and Obsidian are both local-first, Markdown-based knowledge-management apps that get compared often, since both let you keep full ownership of your note files and both have active plugin ecosystems. The clearest differences are in the underlying data model and the license.
Core unit
- SiYuan:
- Block (paragraph, heading, list item, etc.)
- Obsidian:
- File (one Markdown file per note)
Storage format
- SiYuan:
- Internal database referencing blocks; exportable to Markdown
- Obsidian:
- Plain local Markdown files by default
License
- SiYuan:
- AGPL-3.0, fully open source
- Obsidian:
- Free to use; closed source
Built-in AI features
- SiYuan:
- Yes — writing assistant and Q&A chat via configurable provider
- Obsidian:
- Not built-in; available via community plugins
Cloud sync
- SiYuan:
- Optional paid official sync, or self-host via Docker/third-party (S3/WebDAV via PRO)
- Obsidian:
- Optional paid official Sync add-on, or third-party/self-hosted sync via plugins
Mobile apps
- SiYuan:
- Android, iOS, HarmonyOS
- Obsidian:
- Android, iOS
If your priority is fully open-source software and block-level (not just file-level) referencing, SiYuan's data model is the more granular of the two. If your priority is plain-Markdown-file portability and the largest existing plugin/theme ecosystem, Obsidian is worth evaluating directly at obsidian.md. PromptQuorum does not currently have a dedicated Obsidian review to link here — this comparison is based on Obsidian's own site, not a separate PromptQuorum test of Obsidian.
Who Should Use SiYuan?
Whether SiYuan fits depends on whether you want block-level (not just page-level) linking, full data ownership, and optional AI features in one self-hosted app.
Use SiYuan if
- You want a note-taking app that stores your data fully on your own device by default, with cloud sync as an explicitly optional paid add-on
- You want to reference, embed, and link individual blocks (not just whole documents) across your notes
- You want built-in database blocks and a spaced-repetition flashcard system in the same app as your notes
- You want the option to connect your own AI provider (cloud or self-hosted) for writing help or Q&A over your notes, without a required subscription
- You want the underlying application to be open source (AGPL-3.0) and self-hostable, including running your own sync server via Docker
Wait, or look elsewhere, if
- You want your raw notes stored as plain portable Markdown files on disk by default — SiYuan uses an internal block-based database, with Markdown available as an export/import format rather than the native storage format
- You need the largest possible third-party plugin and theme ecosystem — Obsidian and Logseq both have larger, longer-established plugin communities
- You want a completely free official cloud sync with no paid tier — SiYuan's official sync service is part of its PRO/Subscription pricing
- You need official enterprise support with an SLA — SiYuan's support channels are GitHub Issues and community forums, typical of an open-source project rather than a commercial vendor
SiYuan vs. Other Knowledge-Management Tools
SiYuan sits in a small field of local-first, block- or file-based knowledge-management apps. PromptQuorum does not yet have dedicated FeatureAppPost reviews for Obsidian or Logseq themselves as standalone apps — the closest existing reviews in this sub-segment are noted below, alongside the two most relevant external comparisons. See the Local LLM Software Directory for the full catalog.
- Khoj — a self-hosted, open-source "second brain" AI assistant that indexes and chats over your own notes and documents; the closest existing PromptQuorum review in the personal-knowledge-assistant segment. See the Khoj AI review.
- Logseq Copilot — an AI browser-extension/plugin add-on for the open-source outliner app Logseq, rather than a standalone knowledge-base app like SiYuan; still the closest existing PromptQuorum review that touches block-based, local-first note-taking. See the Logseq Copilot review.
- Obsidian — a closed-source but widely used local-Markdown-file note app with a very large plugin/theme ecosystem; see the dedicated comparison section above (no separate PromptQuorum review of Obsidian exists yet).
- Logseq — an open-source, local-first outliner with a block-based, bidirectionally linked structure conceptually closer to SiYuan than Obsidian's file-based model; see logseq.com directly, since PromptQuorum does not yet have a standalone Logseq app review.
Common Mistakes When Evaluating SiYuan
Most confusion about SiYuan comes from assuming it stores plain Markdown files like Obsidian, misunderstanding what the paid tiers actually gate, or assuming its AI features require a specific paid provider.
Mistake 1: Assuming SiYuan stores plain Markdown files on disk
Unlike Obsidian, SiYuan's native storage is an internal block-based database, not a folder of plain .md files. Markdown import/export is supported, but the native format is block-oriented — check this if file-level portability outside SiYuan is a hard requirement for you.
Mistake 2: Assuming the paid tier is required to use SiYuan at all
The free tier has no time limit and no feature gate on core note-taking, block linking, plugins, database blocks, or spaced repetition. The paid PRO and Subscription tiers only add official cloud sync, third-party sync targets (S3/WebDAV), and a cloud inbox.
Mistake 3: Assuming SiYuan's AI features require a specific paid AI subscription
SiYuan's AI features connect to whatever OpenAI-compatible provider you configure — that can be a paid cloud API, or a free self-hosted backend such as Ollama. SiYuan itself does not bundle or require a specific paid AI plan.
Mistake 4: Confusing "local-first" with "no cloud option at all"
SiYuan is local-first, not local-only. It offers an official paid cloud sync service and can also sync to third-party targets like S3/WebDAV (PRO tier) — data simply is not required to leave your device unless you turn one of those on.
Frequently Asked Questions
What is SiYuan?
SiYuan (b3log.org/siyuan, source at github.com/siyuan-note/siyuan) is a free, open-source, self-hosted knowledge-management app built around a block-level editor with bidirectional links, developed by the B3log organization.
Is SiYuan free?
Yes, the core app is free forever with no feature gate on local use. Paid PRO ($64 one-time) and Subscription ($148 one-time/lifetime) tiers only add official cloud sync, third-party sync (S3/WebDAV), and a cloud inbox — see SiYuan's pricing page for current figures.
Is SiYuan open source? What license does it use?
Yes. SiYuan is licensed under AGPL-3.0, per the LICENSE file in its GitHub repository.
Does SiYuan store my notes locally?
Yes, by default. Notes and blocks are stored fully on your own device unless you explicitly enable the official cloud sync service or configure a third-party sync target.
Does SiYuan work like Obsidian?
They are both local-first, Markdown-friendly knowledge-management apps, but the core data model differs: SiYuan's native unit is the block (with an internal database), while Obsidian stores each note as a plain Markdown file. See the dedicated SiYuan vs. Obsidian section above.
Does SiYuan have AI features?
Yes. SiYuan includes an AI writing assistant and Q&A chat that connect to an LLM provider you configure via an OpenAI-compatible API — including self-hosted backends such as Ollama, not only paid cloud providers.
What platforms does SiYuan support?
Windows, macOS, Linux, Android, iOS, and HarmonyOS, per the official download page, plus a self-hostable Docker-based server/web mode.
Can I self-host SiYuan sync instead of paying for the official cloud?
Yes. SiYuan's PRO tier supports syncing to your own third-party storage such as Amazon S3 or a WebDAV server, and the official Docker image lets you run a self-hosted server/web instance as well.
Who develops SiYuan?
SiYuan is developed by B3log (Yunnan Liandi Technology Co., Ltd.), an organization that also maintains other open-source tools such as the Solo blogging engine.
What is SiYuan's latest version?
As of this review, the latest stable release is version 3.8.4 (September 17, 2026) — check the official GitHub releases page for anything shipped after this review's publish date.
Does SiYuan support spaced repetition / flashcards?
Yes. SiYuan includes a built-in flashcard system based on the FSRS (Free Spaced Repetition Scheduler) algorithm, letting you turn existing blocks in your notes into review cards.