About MDConvert

MDConvert is a free, open-source tool that converts common file formats into clean Markdown (.md) entirely inside your web browser. There is no backend server, no file upload, and no data transmission. Every byte of your file is processed locally on your own device using client-side JavaScript.

100% local processing. All conversions happen locally in your browser. Your data never leaves your device. No files are uploaded, stored, or shared.

Supported Formats

HTML → Markdown

Converts HTML documents to clean Markdown. Uses the Turndown library to produce readable, well-structured Markdown output from any HTML source.

Word (.docx) → Markdown

Extracts text and basic formatting from Microsoft Word documents using Mammoth.js, then converts the result through Turndown to Markdown. Handles headings, paragraphs, lists, and tables.

PDF → Markdown

Extracts text from PDF files using PDF.js. Includes basic structural heuristics (font-size-based heading detection, paragraph grouping). Note that PDF is a layout format, so perfect structural recovery is not guaranteed — but you will get clean, readable text.

Image (PNG/JPG) → Markdown (OCR)

Performs optical character recognition on images using Tesseract.js with English and Korean language support. A progress bar shows model download and recognition status.

JSON / Source Code → Markdown

Wraps source code in fenced code blocks with auto-detected language tags. Supports JavaScript, TypeScript, Python, Java, C, C++, C#, Go, Rust, Ruby, PHP, Swift, Kotlin, YAML, XML, SQL, shell scripts, and more.

CSV → Markdown

Converts CSV data into clean Markdown tables with pipe-separated columns. Handles quoted fields and commas inside quotes correctly.

Why Local Processing?

  • Privacy: Your documents never leave your computer.
  • Security: No man-in-the-middle, no server breaches, no data logging.
  • Speed: No network latency — conversions start instantly.
  • Offline-capable: Once the page is loaded, the core converters work offline.

Technology

Built with Vite, vanilla JavaScript, Tailwind CSS, and powered by battle-tested open-source libraries including Turndown, Mammoth.js, Tesseract.js, PDF.js, Marked, and DOMPurify.