← toolkit.bot

Heptabase and PDF to EPUB — How to Build a Visual Knowledge Map from Your Academic Reading (2026)

Heptabase is a visual knowledge management app that organises thinking spatially on interactive whiteboards. Unlike linear note-taking apps, Heptabase lets you place cards on a canvas and draw connections between them — making it well suited for synthesising multiple research papers, mapping a theoretical framework, or planning a literature review.

The reading phase — working through long academic PDFs — is better done on an e-reader than in a browser PDF viewer. Converting to EPUB lets you read on a Kindle or Kobo with adjustable font and night mode, build up highlights, and then bring those highlights into Heptabase as the raw material for your visual knowledge map.

Visual PKM Apps Compared

App	Primary metaphor	PDF annotation	Visual mapping	E-reader sync	Best for
Heptabase	Whiteboard + cards	Built-in	Excellent (spatial)	Via Readwise / manual	Visual synthesis, lit review
Obsidian	Linked documents	Plugin	Graph view (force-directed)	Via Readwise	Long-term knowledge graph
Logseq	Outliner + graph	Built-in	Graph view	Via Readwise	Daily notes + PKM
Roam Research	Outliner + bidirectional links	Limited	Graph view	Via Readwise	Dense networked thinking
Miro / Mural	Team whiteboard	No	Full canvas	No	Collaborative workshops
Notion	Structured database	Limited	No (flat)	Via Readwise	Team wikis, databases

The EPUB → Heptabase Workflow

Download the PDF from your database (arXiv, PubMed, JSTOR, institutional library).
Convert to EPUB via toolkit.bot.
Read on Kindle or Kobo — highlight key passages, definitions, and conclusions you want in your knowledge map.
Export highlights — via Readwise (syncs Kindle highlights automatically) or from the Kobo library on desktop.
Create a Heptabase card for the paper — title it with author + year + short title. Paste highlights as bullet points.
Place on a whiteboard — open your literature review whiteboard and drag the card in.
Connect to related cards — draw visual links to papers with similar findings, contradicting conclusions, or shared methodology.
Add synthesis cards — write your own interpretation cards and link them to the source cards they summarise.

Literature Review Whiteboard Layout Tips

Cluster by theme: group papers spatially by their key contribution — methodology cluster, theory cluster, empirical findings cluster.
Colour-code by quality: use card colours to indicate study design (RCT, qualitative, review) or evidence strength.
Add a synthesis layer: place your own conclusion cards in the centre, linking out to the source papers that support each claim.
Timeline view: arrange papers left-to-right by publication year to trace how a field evolved.
Contradiction cards: mark papers that contradict each other with a red link — this is where the interesting questions live.

Frequently Asked Questions

What is Heptabase and how does it differ from Obsidian?

Heptabase is a visual knowledge management app centred on a whiteboard-based card system. You write notes as cards and arrange them spatially on whiteboards to show relationships. Unlike Obsidian (which is primarily a linked-document / markdown graph tool), Heptabase emphasises spatial visual thinking. It also has a built-in PDF annotator, but converting to EPUB first allows deep reading on an e-reader with a much better reading experience than a browser PDF viewer.

Can Heptabase import PDF annotations or EPUB highlights directly?

Heptabase has a built-in PDF viewer that lets you annotate directly. However, for long-form reading (papers over 20 pages), e-readers offer superior ergonomics. The recommended workflow is: convert PDF to EPUB → read on Kindle or Kobo → export highlights → create Heptabase cards from key passages. Readwise can bridge the gap automatically: it syncs Kindle highlights and can push them to any PKM app via API or copy-paste.

What types of academic content work best with a Heptabase visual map?

Heptabase's whiteboard model is especially powerful for: literature reviews (placing papers as cards and drawing connections between findings), theoretical frameworks (mapping concepts and their relationships spatially), project planning (connecting research questions to source papers and next steps), and multi-paper synthesis (laying out papers in a 2×2 grid by methodology or conclusion type).

Is Heptabase suitable for STEM or is it mainly for qualitative research?

Heptabase works well for both. STEM researchers use it for mapping experimental workflows, connecting methods papers to their protocols, and synthesising results across replication studies. Humanities and social science researchers use it for qualitative coding, theoretical mapping, and argument development. The spatial whiteboard format is flexible enough for any knowledge structure.

How do I set up a Heptabase literature review whiteboard?

Create a whiteboard in Heptabase for your literature review topic. For each paper: read on e-reader, export highlights to Readwise or copy manually, create a Heptabase card titled with the paper citation, paste key highlights as bullet points inside the card. Then arrange cards spatially: group by theme, draw visual links for conceptual connections, and add synthesis cards summarising your own conclusions across clusters.