Questions, bug reports or feature requests: use the support form. Please include your macOS version and Leaflet version (Leaflet menu → About Leaflet).
A diagram or equation shows as code. If Leaflet can't draw a Mermaid diagram or a math block, it shows the source instead. Check the syntax first; if it still won't render, send us the block and your macOS version.
Which files can Leaflet open? Markdown files (.md, .markdown and variants such as .mkd, .rmd and .qmd) and plain text (.txt) render as Markdown. Logs, CSV and TSV, JSON, YAML, TOML, INI and config files, diffs, subtitles, base64 text, hex dumps and checksum lists open in a plain monospace view that shows the text exactly as written. Binary files are not opened, and files over 1 MB are shown in part with a notice.
Leaflet won't open a linked file. Leaflet only reads what you choose to open. A link to a file outside the folder you opened asks you to grant access first.
Pressing Space on a Markdown file shows plain text, not a rendered page. Leaflet's preview extension may need switching on. Follow these steps:
Launch Leaflet from your Applications folder, then quit it. This lets macOS find its preview extension.
Choose Apple menu > System Settings > General > Login Items & Extensions, then find Quick Look under Extensions.
Turn on Leaflet Quick Look and click Done.
Hold Option, Control-click (or right-click) the Finder icon in the Dock, and choose Relaunch. If it still shows plain text, log out and back in.
Select a .md file in Finder and press Space.
Double-clicking a Markdown file doesn't open Leaflet. Leaflet never takes over your files on its own. Make it the default:
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.
Leaflet collects no data and never changes your files. Read the full privacy policy.