A small, fast markdown viewer for Windows, macOS and Linux. It's a single executable with no installer and no runtime to set up.
Click a screenshot to see it full size.
- Tabs: open several files at once, reorder them or move them between windows; opening a file again switches to its existing tab
- Dark mode by default, with a light theme
- GitHub-flavoured markdown: tables, task lists, footnotes, strikethrough, autolinks, definition lists and raw HTML (sanitised)
- Syntax highlighting for fenced code blocks, with a one-click copy button
- Sortable tables: click a column heading to sort it
- Save as PDF or print, always in light colours
- Mermaid diagrams and KaTeX maths, drawn in the app (no internet needed)
- Table of contents sidebar that follows your place in the document
- Find in document, including parts of large files not yet on screen
- Live reload when the file changes on disk, plus a reload button
- Adjustable font size, line spacing, content width and font
- Word wrap for code blocks and tables, which can be turned off
- Handles large files (tested to 25 MB) by rendering only what's near the screen
- Opens local
.mdlinks in a new tab; web links open in your browser - Safe with files from anywhere: documents can't run script, and images from the web only load if you agree (see SECURITY.md)
Get the latest build from the Releases page.
| Platform | File | Notes |
|---|---|---|
| Windows 10/11 | md-viewer-*-windows-amd64.exe |
Uses Microsoft Edge WebView2, which Windows 10 and 11 already include. |
| macOS 11+ | md-viewer-*-macos-universal.zip |
Unzip and move md-viewer.app to Applications. The app isn't signed, so the first time, right-click it and choose Open, or run xattr -cr /Applications/md-viewer.app. |
| Linux (x86-64) | md-viewer-*-linux-amd64.tar.gz |
Needs WebKitGTK 4.1, e.g. sudo apt install libwebkit2gtk-4.1-0 on Debian or Ubuntu. |
Open files with Open (Ctrl+O), by dropping them on the window, or from the command line. Each file gets its own tab:
md-viewer notes.md README.md
Drag a tab along the strip to reorder it, outside the viewer to open a new window, or onto another window's tab strip to move it there. Press Escape to cancel. Dropping inside a document cancels the move. Reading position and image consent follow the tab; its source window closes if it has no tabs left. Detaching by an outside drop requires Windows, macOS or Linux with X11; on Wayland, an outside drop cancels the move.
Files stay open in one tab across all windows. New files from another launch open in the most recently focused window. Tabs aren't restored on startup.
To make it the default app for .md files on Windows, right-click a markdown
file, choose Open with › Choose another app, browse to md-viewer.exe and
tick Always use this app.
Click the printer button (Ctrl+P). MD Viewer renders the whole document and opens the system print dialog. To get a PDF, choose:
- Save as PDF as the destination on Windows,
- PDF › Save as PDF on macOS,
- Print to File on Linux.
The PDF uses light colours whatever theme you're using. Very large files can take a while to prepare, and you can cancel this.
On macOS, use ⌘ in place of Ctrl (except for Ctrl+Tab, which is the same on every platform).
| Action | Shortcut |
|---|---|
| Open file (new tab) | Ctrl+O |
| Close tab | Ctrl+W, or middle-click the tab |
| Next / previous tab | Ctrl+Tab / Ctrl+Shift+Tab (or Ctrl+PgDn / Ctrl+PgUp) |
| Go to tab 1–8 / last tab | Ctrl+1 … Ctrl+8 / Ctrl+9 |
| Reload | F5 or Ctrl+R |
| Save as PDF / print | Ctrl+P |
| Table of contents | Ctrl+B |
| Find | Ctrl+F, then Enter / Shift+Enter (or F3 / Shift+F3) |
| Larger / smaller text | Ctrl+= / Ctrl+- or Ctrl+mouse wheel |
| Reset text size | Ctrl+0 |
| Toggle word wrap | Alt+Z |
| Toggle dark / light | Ctrl+Shift+D |
Settings are saved to md-viewer/settings.json in your user config folder
(%AppData% on Windows, ~/Library/Application Support on macOS,
~/.config on Linux).
You need Go 1.26.9 or newer and the Wails v2 CLI:
go install github.com/wailsapp/wails/v2/cmd/wails@v2.16.0
Then, from the repository root:
wails build # for the current platform
wails build -platform windows/amd64 # Windows (can be built from Linux or macOS)
wails build -tags webkit2_41 # Linux with WebKitGTK 4.1
The executable is written to build/bin/. Linux builds need
libgtk-3-dev and libwebkit2gtk-4.1-dev.
Run the tests with go test ./.... For quick work on the interface,
go run ./cmd/devserver file.md serves the frontend to an ordinary browser at
http://127.0.0.1:8080. scripts/screenshots.mjs regenerates the screenshots
above (see the comment at the top of the file).
Frontend assets are already bundled; Node.js 22.22.1 and npm are only needed
for vendor maintenance. CI uses that Node.js version to verify generated assets.
Compression uses a pinned JavaScript library to avoid system zlib differences.
Run bash scripts/update-vendor.sh to rebuild from scripts/vendor/package-lock.json,
or bash scripts/update-vendor.sh --check to verify the checked-in assets. To update
dependencies, edit scripts/vendor/package.json, regenerate its lock with npm,
audit it with npm audit --prefix scripts/vendor --audit-level=info, then rebuild
and update THIRD-PARTY.md.
Markdown is parsed in Go with goldmark. A document is split into chunks of about 16 KB, and each chunk's HTML is rendered only when it scrolls near the view. Chunks far from the view are emptied again. Files over 1 MB are cut into sections at safe block boundaries and parsed in parallel, so a 25 MB file opens in well under a second and memory stays close to the file's size. Mermaid and KaTeX are embedded in the executable, compressed, and only loaded when a document uses them.
Each chunk's HTML is sanitised before the page sees it, and the page's Content-Security-Policy keeps out script and anything from outside the app. SECURITY.md has the details and how to report a problem.
MIT. See LICENSE. Bundled third-party components are listed in THIRD-PARTY.md.