Editor Basics
WYSIWYG editing
Mark renders Markdown inline as you type. Headings, bold, italic, links, images, code blocks, tables, lists, and block quotes all render in place.
Supported elements
| Element | Syntax | Rendered |
|---|---|---|
| Heading | # Title | Styled heading |
| Bold | **text** | text |
| Italic | *text* | text |
| Code | `code` | Inline code |
| Link | [text](url) | Clickable link |
| Image |  | Inline image |
| Table | Pipe syntax | Rendered table |
| Code block | Triple backtick | Syntax-highlighted block |
| Math | $...$ or $$...$$ | KaTeX-rendered formula |
| Mermaid | ```mermaid | Rendered diagram |
| Checkbox | - [x] | Interactive checkbox |
| Footnote | text[^1] and [^1]: note | Linked footnote |
| Callout | > [!NOTE], > [!WARNING], > [!tip] Title, > [!faq]- | Coloured callout; -/+ make it foldable |
| Front matter | --- YAML block at the top | Properties table; click it to edit the YAML |
Callouts
GitHub's five alerts (NOTE, TIP, IMPORTANT, WARNING, CAUTION) and Obsidian callouts render as callouts. Obsidian aliases such as info, tldr, faq, bug or example get their own colour, and an unknown type uses the note style with its name as the title. Add a title after the marker (> [!tip] Before you start). Add - (collapsed) or + (expanded) after the marker to make it foldable; folding never changes the file. HTML and PDF export keep the callouts.
Front matter
A flat YAML front matter block (keys with text, numbers, lists) is shown as a properties table. Click the table to edit the YAML; click anywhere else to see the table again. Nested YAML stays a plain YAML block. Turn the table off in Preferences → Markdown → Show YAML front matter as a properties table.
Images
Paste a screenshot with Cmd+V or drop an image file from Finder into a saved document: Mark copies it into an assets/ folder next to the file and inserts . The folder name is set in Preferences → Image. In the App Store version, Mark asks once for access to the document's folder; if you decline, the image is saved to Mark's own image folder instead.
Tabs
Mark supports multiple tabs. Each tab is an independent document with its own undo history, cursor position, and diff state.
- Cmd+N — New tab
- Cmd+W — Close tab
- Cmd+Tab — Cycle between tabs
Source code mode
Press Cmd+Alt+S to switch to raw Markdown source editing. The source mode uses CodeMirror with syntax highlighting. Press again to return to WYSIWYG mode.
Split View
Press Cmd+Alt+\ or use View > Split View to show the Markdown source and the rendered page side by side for the current tab.
- One pane is editable, the other is a read-only mirror that follows your edits. In WYSIWYG mode you type in the rendered pane; after Cmd+Alt+S you type in the source pane and the rendered pane follows.
- The mirror never changes your file: what you type in the source pane is saved exactly as written.
- Drag the divider to resize the panes (10–90%). Double-click it to swap sides. Both settings are remembered.
- Split View is per tab and off for new tabs. In a window narrower than 800 px it folds back to one pane and comes back when you widen the window. Diff mode hides it.
- Cmd+\ keeps its old job: it toggles the sidebar.
Live reload
When an external process (your AI agent, another editor, a script) modifies the file on disk, Mark automatically reloads the content. The cursor position and scroll state are preserved.
This only applies to clean tabs (no unsaved changes). If you have unsaved edits, Mark will not overwrite them.
Export
Use File > Export to save the document as:
- PDF — rendered through the system print engine
- HTML — styled HTML with the current theme applied