Heptabase vs SiYuan

Heptabase is a visual knowledge base for students, researchers, and lifelong learners. Whiteboards and cards support visual thinking, while a block-based editor, bidirectional links, PDF annotation, daily journals, and a web clipper help organize material. Its AI can explain sources, take notes, and organize a knowledge base from PDFs, YouTube, notes, and journals. Heptabase supports web, Windows, macOS, Linux, iOS, Android, and a Chrome extension, and lists integrations with Readwise and Zotero. The free plan is available through collaboration, allowing edits to shared whiteboards and cards but excluding personal libraries, journals, tag databases, tasks, highlights, and AI features. The desktop app stores data locally, and notes and files are accessible offline. For AWS cloud storage, the company describes encryption in transit and at rest, but not end-to-end encryption. After a subscription or trial ends, users can access and export content indefinitely; creating or editing notes requires renewal. Paid plans start at $8.99/user/mo (annual), with a 7-day trial.

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.