Notion vs SiYuan

Notion is a cloud workspace for organising personal projects and coordinating work. Its pages, blocks, and databases support note sharing and real-time collaboration, and offline access is available. It runs on the web, Windows, macOS, iOS, and Android, with a Chrome extension also listed. Connections include Slack, Google Drive, Figma, GitHub, Zoom, and Microsoft Teams. Notion supports semantic search, AI search or answers, and version history. The Free plan costs $0 per member per month and includes trial AI capabilities and a trial of Notion AI. Free uploads are limited to 5 MB per file, multi-member Free workspaces have a limited number of blocks, and external guests are limited to 10. Plus costs $10 per member per month, and Business costs $20 per member per month; yearly payment saves up to 20%. Paid plans list unlimited guests. Notion says data is encrypted and private, and that Notion AI does not use customer data to train models unless users opt in. Enterprise workspaces get zero data retention with LLM providers.

SiYuan is a personal knowledge management system for building a linked collection of notes. It supports Markdown, block-level references and bidirectional links, and organizes content into blocks with more than 20 block-level and more than 10 span-level element types. Backlinks can be filtered and searched; relationship graphs are available across a notebook and at block level. Databases support relations, rollups and templates, while flashcards use the FSRS spaced-repetition algorithm. Its AI feature connects to OpenAI for writing continuation, translation, summaries, brainstorming and grammar or spelling corrections. SiYuan supports offline access, and the maker describes multi-device synchronization as incremental and end-to-end encrypted. It is available on Windows, macOS, Linux, iOS, Android and the web, with a Chrome/Edge extension, API and Docker self-hosting. The maker says data stays under the user's control on their device. Free access is free; PRO Features is listed at $64 a month with lifetime-use wording, and Subscription at $148 a month with 8GB cloud storage.