Pandoc

Pandoc is the "universal document converter" — a free, open-source command-line tool that moves text between more than 40 formats. It isn't a book formatter with themes and page design; it's the plumbing that gets a manuscript from one format to another cleanly. Authors who draft in Markdown or plain text lean on it to produce well-structured EPUB and HTML, and it's a common first step in a "write in Markdown → Pandoc → Draft2Digital/KDP" workflow.

Why Authors Use It#

• Best for: Technical and nonfiction authors comfortable with a terminal who want repeatable, scriptable conversions rather than clicking through a GUI
• Broad format support: Converts between Markdown, DOCX, HTML, LaTeX, ODT, RST, and EPUB 2/3, plus PDF output via a LaTeX engine
• Cleaner semantic output: Strips Word's ad-hoc direct formatting more aggressively than most converters, often yielding tidier, more standards-compliant EPUB
• Batch and automation: Because it runs from the command line, you can convert dozens of files or rebuild a book from source with a single script
• Completely free: GPL-licensed and actively maintained on GitHub; no tiers, no paywalled features

Limitations#

• Command-line only: No graphical interface and no live preview — the learning curve is real for non-technical authors
• PDF needs a LaTeX install: High-quality PDF output requires installing a separate LaTeX engine, which adds setup friction
• Not a layout tool: For designed print interiors or themed ebooks, pair it with a formatter like Vellum, Atticus, or Affinity Publisher

Alternatives#

• Calibre (free) — a GUI alternative with its own converter and library manager; friendlier for non-technical users, though less precise on semantic cleanup
• Sigil (free) — for hand-polishing the EPUB Pandoc produces at the HTML/CSS level