Logseq vs SiYuan

Logseq is a free, open-source platform for knowledge management and collaboration, with tools for notes, tasks, and PDF annotation. It supports Markdown and Org-mode files, and connects information through block references, backlinks, linked references, and queries. Logseq supports note sharing and real-time collaboration, and lists Zotero as an integration. The product says users keep their data locally and can work fully on-device; offline access is listed. It is available on web, Windows, macOS, Linux, iOS, and Android. A plugin and theme ecosystem extends the app, with the homepage listing more than 150 plugins and at least 30 themes. Logseq Sync provides encrypted file syncing across devices. Its public-beta Sync service does not support multiple people using the same graph at once, and the maker warns that data loss can occur. The database version is in beta, while the new mobile app and real-time collaboration features are in alpha; the maker also warns of possible data loss for these. Personal use is free forever. Sync Backer costs $5 a month and Sync Sponsor costs $15 a month, each described as a monthly recurring donation.

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.