MDViewer

MDViewer is a Windows Markdown viewer and conversion tool built with WinUI 3. It opens Markdown files directly, renders a readable preview, builds a heading outline for navigation, and uses Pandoc when you need to import, export, or crawl content into Markdown.

Features

• Open .md and .txt files directly.
• Render Markdown in a native WinUI 3 preview.
• Toggle between rich preview and raw Markdown.
• Navigate long documents with an automatically generated heading tree.
• View line count, character count, UTF-8 encoding, and zoom level.
• Save Markdown as .md or .txt.
• Format Markdown with normalized spacing, ATX headings, and stable list markers.
• Reflow heading levels into a cleaner hierarchy.
• Import .docx, .html, and .epub into Markdown through Pandoc.
• Export Markdown through Pandoc to .docx, .html, .epub, .rtf, .odt, .tex, .typ, .rst, and .org.
• Crawl documentation sites into Markdown with a conservative single-threaded crawler that respects robots.txt.

Download

Download the latest Windows x64 executable from the GitHub Releases page.

The release is a portable MDViewer.exe, not an installer or MSIX package. You can run it directly, pass a file path such as MDViewer.exe README.md, or use Windows Open with for Markdown files.

Because the executable is unsigned, Windows SmartScreen may show an unknown-publisher warning.

Pandoc

Pandoc is optional for basic Markdown viewing. You only need Pandoc for import, export, and crawl features.

MDViewer looks for Pandoc in this order:

1. pandoc.exe beside MDViewer.exe.
2. Assets\pandoc.exe beside MDViewer.exe.
3. pandoc.exe on PATH.

Use Fetch Pandoc inside MDViewer to download the latest Windows x64 Pandoc release. The app places pandoc.exe beside MDViewer.exe and does not modify user or machine environment variables.

If the folder containing MDViewer.exe is not writable, move the app to a writable folder, place pandoc.exe beside it manually, or install Pandoc yourself and put it on PATH.

Building From Source

Requirements:

• Windows x64.
• Windows 10 version 1809 or newer.
• .NET 10 SDK.

Build:

dotnet build MDViewer.slnx -c Release

Publish a portable single-file Windows x64 executable:

dotnet publish MDViewer\MDViewer.csproj -c Release -r win-x64 --self-contained true -p:PublishSingleFile=true -p:IncludeNativeLibrariesForSelfExtract=true -o Build

The published executable is written to Build\MDViewer.exe.

Notes

• The current release target is Windows x64.
• JavaScript-heavy sites may not crawl cleanly if their content is rendered only in the browser.
• Crawling is intentionally conservative: same-base-path, single-threaded, delayed between requests, and capped at 250 pages.
• Imported and crawled Markdown should be reviewed when source documents contain complex tables, unusual HTML, or hand-written anchor links.

License

MIT License. See LICENSE.