Flexnote vs Heptabase: Where Two Card-Based Whiteboards Differ (2026)

If you're looking for a "cards + infinite whiteboard" visual note-taking tool, both Heptabase and Flexnote will likely show up — and if you're specifically searching for the best Heptabase alternatives, Flexnote is one of the names that comes up most. They look similar — cards hold the content, and an endlessly pannable canvas lets you arrange ideas spatially — but they optimize for different things. This article won't crown an absolute winner; it lays out the key differences so you can choose based on your own needs.

1. Positioning: both built for deep learning and research

Their target audiences overlap heavily — both are built for deep learning and research, helping you connect scattered cards into a system on the whiteboard for literature reviews, course notes, and long-running research. Heptabase has a mature toolset and an active community, and is deeply polished around "thinking complex topics through."

Flexnote is built for the same deep-learning and research use, but takes a different path: it's local-first, leans harder on data privacy and ownership, and pairs that with a self-built high-performance canvas, broader annotation, and a one-time-purchase option — a lighter, more self-directed take on the same "research whiteboard."

2. Canvas and performance: same shape, different foundation

The base unit in both is the card, and both support Markdown, bidirectional links, and free arrangement and linking on a whiteboard. But the rendering foundation is a key difference: Heptabase renders the canvas with DOM-based web technology, while Flexnote uses a self-built high-performance Canvas engine. When a board grows to hundreds of cards with heavy zooming and dragging, a Canvas approach usually stays smoother.

3. Annotation: more than PDF

Research lives on annotating your source material, and here the gap is clear. Flexnote can annotate cards, PDFs, video (including YouTube), and audio — whether your material is a paper, a course video, or a podcast, you can highlight and take notes right on the source and link back to the canvas. Heptabase currently supports PDF annotation only.

4. Local-first, privacy, and publishing

This is where the two differ most in spirit.

• Heptabase: requires an account and online login to use, with the account tied to the cloud; data exports to Markdown and JSON, but a copy is kept on servers and there is currently no end-to-end encryption.
• Flexnote: local-first — you can use it locally without a mandatory online login, and data stays in your hands by default. For cross-device sharing it syncs through third-party cloud storage like Baidu Cloud, OneDrive, S3, and WebDAV, so you decide where your data lives.

Local-first doesn't mean closed off: Flexnote can publish a whiteboard to the web, generating a link anyone can open in a browser, and supports exporting to PDF and other formats — keeping data ownership without giving up sharing.

5. Platforms and collaboration

Heptabase offers Mac, Windows, Linux, iOS, Android, and Web, plus collaborator invites. Flexnote offers Windows / macOS desktop and mobile apps for capturing and reviewing on the go.

6. Pricing

For many people this is the deciding factor, and it differs a lot.

• Heptabase: subscription only, no permanent free tier, with a 7-day trial. Pro is about $8.99/mo billed yearly; more AI credits come via Premium ($17.99/mo) or Premium+ ($53.99/mo).
• Flexnote: has a permanent free tier (100 cards, local storage, single device); paid plans are Pro at $29/quarter or $49/year, plus a $149 one-time lifetime license.

7. At a glance

8. How to choose

Both are built for deep learning and research. If you value a mature ecosystem and AI tooling and full cross-platform collaboration, and don't mind a subscription, Heptabase is a proven, reliable choice.

If you value canvas performance (large boards staying smooth), need full annotation across cards, PDFs, video, and audio, care about local-first data privacy, want to sync across devices flexibly via third-party cloud storage, and prefer starting free or buying once, then Flexnote fits your workflow better and costs less over time.

The two aren't mutually exclusive — they represent two reasonable trade-offs within the same "whiteboard notes" category. The best move is to run your real note-taking scenario through each one's free tier or trial.