Three view modes
Switch between Source, Preview, and Split — side-by-side editing with live render.
Markdown, refined
Write in source. See it live.
UpDown is a lightweight Markdown viewer and editor — native on macOS, instant in the browser. Edit, preview, present slides, and manage files without the bloat.
Split view — edit & preview together
Built for real writing workflows
Everything you need to draft, review, and share Markdown — from quick notes to polished slide decks.
Slide presentations
Marp-style decks with --- separators, themes, keyboard nav, and fullscreen present mode.
Web & desktop
Native macOS app with Quick Look, plus a browser version with guest mode and Google Drive.
Markdown toolbar
Bold, italic, headings, links, images, lists, blockquotes, code blocks, tables, and horizontal rules.
Live preview
Rendered output updates as you type — debounced for smooth performance.
Mermaid diagrams
Flowcharts, sequence diagrams, and more render inline in preview.
Find & replace
Search and replace in the editor with keyboard shortcuts (⌘F / ⌘⌥F).
Bidirectional text
Hebrew and other RTL paragraphs align automatically based on content.
Folder panel
Browse markdown files in a resizable sidebar with persistent state.
File operations
New, open, save, and save as — via toolbar or native dialogs. PDF viewing too.
Drag & drop
Drop .md or .pdf files onto the window to open them instantly.
Autosave
Changes save automatically after a short idle period when a file is open.
Print a formatted preview from the toolbar (⌘P).
Preview zoom
Scale preview from 50% to 200% for comfortable reading.
Quick Look
Press Space in Finder to preview .md files without opening the app.
See it in action
Clean editing surfaces that stay out of your way.
Two ways to use UpDown
Pick the experience that fits — a native desktop app or a zero-install web app.
Web app
Run UpDown in your browser at updown.eshkoli.com/app/. Same editor, slides, find/replace, Mermaid, and print.
- Guest mode — open local files via drag-and-drop or file picker
- Google Drive — sign in to browse, save, and create folders
- No install required — works on any modern browser
macOS desktop
A native app built with Tauri 2 — small footprint, system WebView, and macOS integrations like Quick Look.
- Folder panel for local project navigation
- Native open/save dialogs and autosave
- Quick Look plugin for Finder previews
Install on macOS
Apple Silicon build — drag to Applications and start writing.
- Download the latest UpDown_X.Y.Z_aarch64.dmg from GitHub Releases.
- Open the DMG and drag UpDown into Applications.
- Eject the disk image, then launch UpDown from Applications.
First launch — Gatekeeper
macOS may show "UpDown is damaged and can't be opened." Run this once in Terminal:
xattr -d com.apple.quarantine /Applications/UpDown.app
Start writing in UpDown
Open the web app in seconds, or download the macOS app for offline work.