MDHero Personal is AutomaticLasagna's fork. See FORK.md for its changes, build commands, and verification. Download links below belong to the original project.
A beautiful, native Markdown viewer and lightweight editor for macOS, Windows and Linux. ~8MB. Free. Open source.
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| Light mode | Dark mode |
Open local .md files, paste AI-generated markdown, or fetch from any public URL — and read or edit it the way it was meant to be.
Markdown is where developers, writers, and AI live today — READMEs, Claude Code plans, LLM chat exports, notes, documentation. But opening a .md file in a code editor gives you ugly monospace text. Opening a web-based viewer means uploading your files. GitHub renders it beautifully but only if the file is in a repo.
MDHero is a native app for everything in between. Your files stay local. Rendering is instant. Edit in place when you need to. Works offline. Looks like it belongs on your machine.
- Beautiful rendering — Apple-inspired typography, light & dark themes
- Syntax highlighting — 25+ languages via highlight.js
- Math & diagrams — KaTeX for equations, Mermaid for flowcharts
- Reader controls — adjust font, size, line height, width
- Zen mode — distraction-free full-screen reading
- Print/Export to PDF — File › Print or Cmd/Ctrl+P opens the native print dialog (print to paper or to PDF), with clean print styles
- Lightweight in-app editor —
Cmd+Eflips any local file into edit mode - Markdown highlighting — headings, emphasis, links, lists, quotes and code are colored as you type, in light and dark (Settings › Editor to turn it off)
- Save with
Cmd+S— writes back to disk; the file watcher knows it was you and skips the reload - Undo and redo —
Cmd+Z/Shift+Cmd+Z(alsoCtrl+Yon Windows and Linux), a word at a time, with a separate history for each tab that survives switching tabs, toggling edit mode and saving - Stays where you were — source-line scroll sync keeps your position across viewer ↔ raw ↔ edit
- Dirty indicator —
•in the tab title and toolbar when you have unsaved changes - Per-tab edit state — switch tabs and back; your edits are right where you left them
- Multiple tabs — open many files, drag to reorder, Cmd+1–9 to switch
- Tabs on the side — move the tabs into a resizable panel on the left, with a file's folder under its name when another open file has the same name
- Table of Contents — auto-generated sidebar with active heading tracking
- Search (Cmd+F) — with match highlighting
- Vim keys — j/k/gg/G/d/u/[/] for keyboard-first navigation
- Image lightbox — click to zoom, arrow keys for next/prev
- Local files — drag-drop, Cmd+O, "Open With" from Finder
- Pinned folders — quick access to markdown in your favorite directories
- Claude Code Plans — auto-discovers
~/.claude/plans/ - Open URL — fetch from GitHub, Gist, GitLab, Bitbucket, or any public URL
- Paste mode (Cmd+Shift+V) — render LLM output instantly, auto-unescapes
\n - Recent files — pick up where you left off, with reading progress per file
- File watching — edit in VS Code, see updates instantly in MDHero
- Auto-reload — survives atomic saves (VS Code, vim, etc.)
- Copy as Rich Text — paste directly into Google Docs, Notion
- Copy as Markdown — raw source
- Print / Export PDF — File › Print, Cmd/Ctrl+P, or the toolbar button; print-friendly output
25+ languages with automatic detection, copy button, and clean typography.
Render LaTeX equations instantly — from inline math to full block equations and matrices.
Flowcharts, sequence diagrams, class diagrams, and more — rendered natively.
Distraction-free full-screen reading. Just you and the document.
macOS (Apple Silicon): Download .dmg from Releases →
Windows (x64 or ARM64): Download .msi or -setup.exe from Releases → — pick the x64 or arm64 file for your machine
Linux (x64 or arm64): Download .deb (Debian/Ubuntu), .rpm (Fedora/openSUSE) or .AppImage (any distro) from Releases → — amd64/x86_64 or arm64/aarch64
Or build from source (see below).
| Shortcut | Action |
|---|---|
Cmd+O |
Browse files |
Cmd+Shift+V |
Paste markdown |
Cmd+T |
New tab (home) |
Cmd+W |
Close tab (confirms if unsaved edits) |
Cmd+1..9 |
Switch to tab N |
Cmd+F |
Find in document |
Cmd+E |
Toggle edit mode |
Cmd+S |
Save edits to disk |
Cmd+Z / Shift+Cmd+Z |
Undo / redo an edit |
Cmd+U |
Toggle raw markdown view |
Cmd+Shift+F |
Zen mode |
Cmd+= / Cmd+- |
Zoom in / out |
Ctrl + mouse wheel |
Zoom in / out (Ctrl on every platform) |
Cmd+0 |
Reset zoom |
j / k |
Scroll down / up |
gg / G |
Jump to top / bottom |
[ / ] |
Previous / next heading |
/ |
Open search |
Cmd → Ctrl on Windows/Linux.
pnpm install
pnpm tauri dev # Run dev with hot reload
pnpm tauri build # Production build (outputs DMG/MSI)
pnpm check # TypeScript checkRequirements: Node 22+, Rust stable, pnpm 10+.
Port 1420 is used for dev. Kill stale processes with lsof -ti:1420 | xargs kill -9.
- Tauri v2 — Rust backend, ~11MB binary
- SvelteKit — frontend with Svelte 5 runes
- markdown-it — rendering pipeline
- highlight.js — syntax highlighting
- KaTeX — math rendering
- Mermaid — diagram rendering
- Tailwind CSS v4 — styling
MDHero runs entirely on your machine.
- No telemetry. No analytics. No tracking.
- No account required. Use it anonymously.
- Your files never leave your computer. Rendering happens locally.
- Network access is limited to: asking GitHub whether there is a newer release (once per 24h, sending nothing about you; you can turn this off in Settings) and fetching URLs you explicitly paste into the Open URL feature. See SECURITY.md for exactly what each request contains.
Coming next:
- Quick Switcher (Cmd+P fuzzy finder)
- Folder watch (auto-refresh pinned folder contents)
- Export to self-contained HTML
- Presentation mode
- Compare / diff view
See CONTRIBUTING.md for setup, guidelines, and how to propose changes.
MIT © Vaibhav Kakde