Heptabase vs SecondBrain

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.

SecondBrain turns spoken thoughts, typed notes and content shared from other apps into organized notes, calendar events and reminders. Its AI transcribes, titles and files notes into a folder tree that builds as material is added. Mentioning a date can create an event and reminder, and the app provides a daily morning briefing. Full-text search and an interactive 3D graph help users find notes and explore connections. A shared-memory connector using MCP supports assistants including Claude, ChatGPT, Gemini, Cursor and Claude Code. The connector requires Pro, and connecting ChatGPT also requires Developer mode, which the maker says is available on Plus or above. The maker says notes and calendar events are stored in an EU-hosted Supabase PostgreSQL database with per-account Row-Level Security; voice and text go through Google Gemini's paid API tier, which it says does not train on content. The free plan has limited notes. Pro is $8.99 a month or $34.99 a year; the App Store also lists a second yearly price of 44.99 USD.