Docs

Install and start

Mac: Download the signed DMG, open it, and drag Sideleaf to Applications. Sideleaf needs Apple Silicon and macOS 26.6.2 or later.

Windows: Download and extract the setup ZIP, then run Setup. Sideleaf needs Windows 11 x64 and WebView2. The installer is not signed yet, so Windows can show a publisher warning.

Linux: There is no packaged Linux build yet. You can build Sideleaf from the sources.

Download Sideleaf 0.1.4 or read the release notes and checksums.

Documents

Use New for an empty document, Open for a file picker, or open a .md, .markdown, or .mdown file from Finder or Windows. Find searches the source and can replace matches.

Write in the left editor. The right preview updates as you type. Sideleaf saves the Markdown you wrote instead of rebuilding it from the preview.

Sideleaf keeps one document open at a time. If the current document has unsaved changes, New, Open, Close, and Quit ask whether to save, discard, or cancel.

Views and layouts

Write, Split, and Read

Write gives the editor all available space. Split shows the editor and preview together. Read gives the preview all available space.

Minimal layout

Minimal layout removes the large app header. File actions, the file name, Comments, Settings, and the Sideleaf menu move into the title bar. Turn it on in Settings or use its shortcut. Your choice is kept for the next launch.

Distraction-free mode

Distraction-free mode fills the screen and removes normal menus and controls. Write, Split, Read, Comments, and their shortcuts still work. Press Escape to leave.

Comments

Select text and choose + Comment. If nothing is selected, the comment applies to the current line. You can also use the Add comment shortcut.

The Comments button opens or closes the review sidebar. Comments move with nearby edits, participate in undo and redo, and show when their original text can no longer be found.

Comments are stored in a Sideleaf metadata block at the end of the Markdown file. The editor and preview hide that block, but the comments still travel with the file.

Saving and recovery

Save writes the current named file. Save As writes a new Markdown file and keeps the old file unchanged.

Auto-save runs every 30 seconds when it is enabled. A named document saves to its file. Restore untitled draft keeps one unsaved new document in Sideleaf's private app data and restores it after a restart.

If another app changes the file while your Sideleaf draft is clean, Sideleaf reloads it. If your draft is dirty, Sideleaf keeps your work and reports a conflict instead of overwriting either copy.

Settings

Open the cog button in the title bar. You can change:

• Appearance: Light, Dark, or System.
• Wrap long lines.
• Auto-save every 30 seconds.
• Restore one untitled draft.
• Minimal layout.

The footer also has Light, Dark, and System buttons. The zoom control changes editor and preview text together from 70% to 180% in 10% steps.

Make Sideleaf the default editor

Choose Make default editor from the Sideleaf menu. On Mac, Sideleaf shows the Finder steps. On Windows, it opens Default Apps for Sideleaf. The operating system makes the final change.

You can keep another default and still choose Sideleaf from Open With.

Command line

Choose Install command line tools from the Sideleaf menu. Windows Setup can also install the command. On Windows, Install command-line tools in WSL adds a small wrapper to the default WSL distribution.

The command uses the runtime inside the installed app. You do not need Node, Bun, or npm.

sideleaf --help
sideleaf open notes.md
sideleaf read notes.md
sideleaf comments notes.md

The help output explains agent-friendly read, edit, and comment commands, revision checks, JSON input, and actor names. See the complete command-line reference.

Keyboard shortcuts

These are Sideleaf's custom shortcuts. The in-app Sideleaf menu has the same list.

Standard shortcuts

New, Open, Save, Close, Find, Undo, Redo, and Quit use the normal Command shortcuts on Mac and Control shortcuts on Windows. Save As uses Ctrl Shift S on Windows. On Mac, choose Save As from the File menu because Cmd Shift S switches to Split.