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Usman
Usman

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I got tired of paywalls for Markdown converters, so I built a free, 100% client-side alternative.

#javascript #webdev #productivity #showdev

As a software engineer, I write almost everything in Markdown. It's fast, clean, and lives easily in Git. But sharing those documents with non-technical clients or teammates usually requires converting them into PDFs or Word documents.

When I went looking for tools to handle this, I hit two major roadblocks:

  • Privacy: Most free online converters require you to upload your files to a backend server. For private code documentation, internal wiki pages, or client notes, that's a real security risk.
  • Paywalls: The tools that actually handled clean formatting or two-way conversions (especially for Word .docx files) were almost entirely gated behind monthly subscriptions.

So I decided to build it myself.

MDTool is a free, browser-based Markdown conversion suite that processes everything locally on your machine. Zero server uploads. Zero sign-ups. And it's open source on GitHub under the MIT license, so you can check exactly what happens to your files.

The 7 tools included

Instead of making you jump between single-purpose websites, everything lives in one workspace:

  • Markdown to PDF: Real vector PDFs with selectable, searchable text (not a screenshot of the page). Renders Mermaid diagrams, highlights code blocks, and has 4 themes (GitHub, Academic, Minimal, Dark) on A4 or US Letter.
  • Markdown to Word (.docx): Builds a genuine Word document rather than a renamed HTML file. Headings map to Word's built-in Heading 1-6 styles, so the navigation pane and automatic table of contents work, and tables and nested lists stay editable.
  • Markdown to HTML: Clean, semantic HTML as a snippet or a full document.
  • Markdown to Plain Text: Strips the Markdown syntax while keeping paragraphs, lists and table rows readable.
  • Word (.docx) to Markdown: Drag in a Word file and get clean Markdown back, with the hidden proprietary styling stripped out.
  • HTML to Markdown: Paste raw HTML and get GitHub Flavored Markdown, handy for moving legacy web copy into docs.
  • Markdown Table Generator: A visual grid with column alignment and paste-from-Excel/Google Sheets.

How it works under the hood

To keep everything 100% client-side, the app is built with Next.js and a handful of open-source libraries that run in the browser:

  • marked parses the Markdown, with highlight.js for code and Mermaid for diagrams.
  • pdfmake lays out the PDF as real vector text, which is why the output stays selectable and searchable.
  • The docx library builds proper OpenXML Word files from the Markdown structure.
  • mammoth.js and turndown (with the GFM plugin) power the reverse direction, Word and HTML back to Markdown.

The heavy engines are only loaded when you actually convert something, so the pages stay fast, and your content never leaves your browser.

Try it out

I built this toolkit to solve my own workflow problems, but I'm hoping it saves some of you a few dollars and a few security headaches.

Everything is free at mdtool.dev, and the code is at github.com/usmankhan045/mdtool.

I'd love to hear your thoughts, especially if you throw heavy nested tables or complex multi-level lists at the Word engine. What tools do you keep in your formatting toolkit?

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