← Marked Home

Marked Help

PDF Support

Marked can open PDF documents (.pdf) directly. Drag a file to Marked or use File Open… (⌘+O). The document is converted to Markdown for preview and export.

PDF import works best on smaller, text-based PDFs (slides, articles, short reports). Large manuals, books, and scanned documents are supported but often convert slowly or imperfectly — see Limitations below.

Marked is still a preview tool: you do not edit the PDF inside Marked. Use ⌘+E to open the PDF in Preview (or your system default), and Marked refreshes when the file changes on disk.

How conversion works

PDF import uses the pdf22md library (MIT License; see pdf22md License). Marked runs conversion in the background while showing a short Converting notice.

The converter:

  • Extracts text from digital PDFs using PDFKit
  • Uses Vision OCR on pages where embedded text is missing (common with scans)
  • Detects headings from font size when possible
  • Saves images into an assets folder next to the generated Markdown

Marked does not enable pdf22md’s optional AI cleanup in the app. Conversion quality depends on how the PDF was created.

Cache and live preview

Converted Markdown and images are stored under Marked’s Watchers cache (~/Library/Caches/Marked/Watchers/PDF/). The original PDF path stays the document source for file watching.

When you save or replace the PDF in another application, Marked detects the change and re-converts automatically (same coalesced reload behavior as RTF and Scrivener).

Export and other features

After conversion, Marked treats the document like other compiled sources: export, statistics, and most preview features run against the generated Markdown. Image paths in the preview point at cached assets until you export.

Limitations

Set your expectations accordingly — PDF-to-Markdown is useful, not perfect.

What works well

  • Vector and text-based PDFs with real embedded text (exported from Word, Pages, InDesign, etc.)
  • Moderate length — a few dozen pages usually convert in reasonable time with good structure

What is unreliable

  • OCR (scanned PDFs) — Vision fills in missing text, but accuracy is often poor compared with a dedicated OCR tool; expect typos, broken words, and missed columns
  • Tables — layout is guessed from text positions; merged cells, nested tables, and complex grids rarely survive as clean Markdown tables
  • Image placement — figures are extracted to assets/, but alignment, captions, and text wrap around images are not preserved reliably

Size and performance

  • Large PDFs (user guides, textbooks, long manuals) may take a very long time to convert, use substantial memory, or fail to produce useful Markdown. Marked stays responsive while conversion runs in the background, but there is no guarantee a 500-page manual will finish successfully
  • If conversion completes with little or no content, Marked shows an error rather than leaving a blank preview

Other limits

  • Password-protected PDFs are not supported in v1
  • Embedded PDF images in Markdown ([]() referencing a .pdf file) are unrelated to PDF import — only opening a .pdf as the main document triggers conversion

For Word documents, use Working with DOCX. For Rich Text, use RTF and RTFD Support.

Related topics

Next up: Image Variants ▶

Search | Support Site | Knowledgebase | Legal | Privacy | Twitter