A lightweight, read-only Markdown viewer for macOS. Double-click a .md file, get clean rendered output — no editing, no accounts, no tracking.
Native, sandboxed, and focused on one job: showing your Markdown files the way they were meant to look.
Handles .md and .markdown files (and variants such as .mkd, .rmd and .qmd), and renders .txt files as Markdown. Logs, CSV, JSON, YAML, config files, diffs, subtitles, base64 text and hex dumps open in a plain monospace view that shows the text exactly as written. It never silently steals the system default — you choose when Leaflet opens a file.
Headers, lists, tables, task lists, strikethrough, autolinks, blockquotes, images, and fenced code blocks with syntax highlighting.
Fenced mermaid blocks render as diagrams, and display math ($$ … $$) renders with KaTeX. Both run from copies bundled inside the app.
Press Space on a .md file for a rendered preview — diagrams and math included — without opening the app.
Open a folder to browse its Markdown files in a sidebar. Links between files open right where you are.
Find text in a document with ⌘F, and jump between headings from a table-of-contents outline.
The document re-renders as the file changes on disk, keeping your place — handy for plans and notes that something else is still writing.
Follow the system appearance or pick light or dark, and adjust the text size to suit you.
Copy a document as plain text, or print it and save a PDF.
There is no save path at all. Leaflet reads the files you open and never writes to or modifies them.
No accounts, no servers, no analytics, no update checks. Leaflet is sandboxed, and your files never leave your computer.
Leaflet never takes over your files on its own. These steps make it the app that opens Markdown, and turn on Space-bar previews.
In Finder, click any .md file once.
Press Command-I, or choose File > Get Info.
Expand Open with and pick Leaflet from the menu.
Click Change All…, then Continue. Double-clicking any .md file now opens it in Leaflet.
Press Space on a .md file in Finder for a rendered preview. This normally works as soon as Leaflet is installed. If you see plain text instead, follow the Quick Look troubleshooting steps.