What is the Zettelkasten method?

Zettelkasten (German: 'slip box') is a note-taking system developed by sociologist Niklas Luhmann. Each note (Zettel) contains a single atomic idea with links to other notes. The system is used by researchers, writers, and knowledge workers to build a networked personal knowledge base. Reading source material carefully and extracting key ideas is a critical first step — and that reading experience is much better in EPUB than PDF.

Why convert PDFs to EPUB for Zettelkasten reading?

Most Zettelkasten source material arrives as PDF — academic papers, reports, ebook chapters. PDFs are fixed-layout and hard to annotate comfortably on a phone or e-reader. Converting to EPUB gives you reflowable text, proper font sizing, and access to the annotation tools built into Kindle, Kobo, Apple Books, or Readwise Reader. Highlights and notes can then be exported to Obsidian, Logseq, Roam, or Notion for permanent notes.

How do I export Kindle highlights to Obsidian or Logseq?

Kindle highlights are stored in My Clippings.txt (accessible by USB) or synced via Readwise. Readwise connects to Kindle, Kobo, and Apple Books and exports highlights to Obsidian (via Readwise Official plugin), Logseq, Roam Research, Notion, and other PKM tools. This creates a reading → annotation → permanent note pipeline that fits cleanly into a Zettelkasten workflow.

Which apps work best for Zettelkasten-style reading and annotation?

Readwise Reader is the most Zettelkasten-friendly EPUB reader: it accepts EPUB uploads, lets you highlight and tag passages, and exports highlights to Obsidian/Logseq/Roam. Kobo e-readers export highlights to CSV. Apple Books highlights can be extracted via the Apple Notes integration or third-party exporters. Kindle highlights sync to Readwise automatically with a Readwise subscription.

Can I use Zotero with EPUB files in a Zettelkasten workflow?

Zotero 6+ supports EPUB storage and annotation. You can attach an EPUB to a Zotero reference entry, annotate it in Zotero's built-in PDF/EPUB reader, and then export annotations to Obsidian via the Zotero integration plugin. This makes Zotero a viable hub for source management in a Zettelkasten workflow — convert your PDFs to EPUB, import into Zotero, annotate, then export notes to your slip box.

Zettelkasten Workflow: Convert PDFs to EPUB for Annotated Reading Before Taking Notes (2026)

Updated June 2026 · Research

The Zettelkasten method starts with careful reading and annotation of source material. Most academic source material arrives as PDF — but PDFs are uncomfortable to annotate on a phone, tablet, or e-reader. Converting to EPUB gives you a better reading environment, and modern annotation tools (Readwise Reader, Kobo, Zotero) can export your highlights directly to your slip box in Obsidian, Logseq, or Roam.

A PDF-to-EPUB Zettelkasten reading pipeline

Step	Tool	What happens
1. Source PDF	arXiv, PubMed, JSTOR, etc.	Download the full-text PDF
2. Convert to EPUB	toolkit.bot	Reflow to readable format
3. Read and annotate	Readwise Reader / Kobo / Kindle / Zotero	Highlight key ideas and tag passages
4. Export highlights	Readwise / CSV / Zotero plugin	Highlights flow to PKM tool
5. Write Zettels	Obsidian / Logseq / Roam / Notion	One atomic idea per note with source link

EPUB readers with the best Zettelkasten integration

Readwise Reader — accepts EPUB uploads directly. Highlights are tagged, synced, and exported to Obsidian, Logseq, Roam, Notion, and others. The most integrated option for digital Zettelkasten users. How to use Readwise Reader with PDFs →
Kobo e-reader — highlights export to CSV or via Kobo's integration with Readwise. Physical e-ink reading is better for long academic texts. How to send PDFs to Kobo →
Zotero 6+ — built-in EPUB reader with annotation. Annotations export to Obsidian via Zotero integration plugin. Best if you already manage references in Zotero. Zotero PDF to EPUB workflow →
Apple Books (iOS/macOS) — highlights can be extracted via Notes integration or third-party exporters. Simple and low-friction for Apple ecosystem users.
Kindle app — highlights sync to Readwise automatically. Use for reading PDFs converted to EPUB and then exported to Readwise → Obsidian. How to send PDFs to Kindle →

Why EPUB is better than PDF for Zettelkasten reading

Readable on any device at any font size — you read better when you're comfortable, and comfort means your preferred font, line spacing, and background
Annotation tools work correctly — PDF annotations on two-column academic papers often mis-select text across columns; EPUB text is linear
Highlights export cleanly — EPUB highlight export to Readwise / Obsidian preserves context without column-break artefacts
Zotero EPUB reader — Zotero 6+ reads EPUB natively, letting you annotate inside your reference manager without a separate reading app

Frequently asked questions

What is the Zettelkasten method?: Zettelkasten (German: 'slip box') is a note-taking system developed by sociologist Niklas Luhmann. Each note (Zettel) contains a single atomic idea with links to other notes. The system is used by researchers, writers, and knowledge workers to build a networked personal knowledge base. Reading source material carefully and extracting key ideas is a critical first step — and that reading experience is much better in EPUB than PDF.
Why convert PDFs to EPUB for Zettelkasten reading?: Most Zettelkasten source material arrives as PDF — academic papers, reports, ebook chapters. PDFs are fixed-layout and hard to annotate comfortably on a phone or e-reader. Converting to EPUB gives you reflowable text, proper font sizing, and access to the annotation tools built into Kindle, Kobo, Apple Books, or Readwise Reader. Highlights and notes can then be exported to Obsidian, Logseq, Roam, or Notion for permanent notes.
How do I export Kindle highlights to Obsidian or Logseq?: Kindle highlights are stored in My Clippings.txt (accessible by USB) or synced via Readwise. Readwise connects to Kindle, Kobo, and Apple Books and exports highlights to Obsidian (via Readwise Official plugin), Logseq, Roam Research, Notion, and other PKM tools. This creates a reading → annotation → permanent note pipeline that fits cleanly into a Zettelkasten workflow.
Which apps work best for Zettelkasten-style reading and annotation?: Readwise Reader is the most Zettelkasten-friendly EPUB reader: it accepts EPUB uploads, lets you highlight and tag passages, and exports highlights to Obsidian/Logseq/Roam. Kobo e-readers export highlights to CSV. Apple Books highlights can be extracted via the Apple Notes integration or third-party exporters. Kindle highlights sync to Readwise automatically with a Readwise subscription.
Can I use Zotero with EPUB files in a Zettelkasten workflow?: Zotero 6+ supports EPUB storage and annotation. You can attach an EPUB to a Zotero reference entry, annotate it in Zotero's built-in PDF/EPUB reader, and then export annotations to Obsidian via the Zotero integration plugin. This makes Zotero a viable hub for source management in a Zettelkasten workflow — convert your PDFs to EPUB, import into Zotero, annotate, then export notes to your slip box.