Markdown editor for macOS · Mac App Store

See it as you write.
Draw your diagrams.

SSEM MarkdownEditor shows the rendered result while you type. Mermaid diagrams, KaTeX math and syntax-highlighted code render right in the preview — and with the new Diagram Studio you can edit diagrams visually instead of hand-tuning code.

Mac App Store · US$0.99 Read the guide

Requires macOS 14 Sonoma or later · One-time purchase (no subscriptions or in-app purchases) · No accounts, ads or analytics · Levelupsoft Inc.

SSEM MarkdownEditor window: Markdown source in the editor on the left, rendered headings, table of contents and table in the preview on the right

New Diagram Studio

Double-click any Mermaid diagram in the preview to open it in Diagram Studio. Apply writes your changes back into the document’s code block, and new diagrams are inserted at the cursor.

Visual flowchart editor

Add, rename and delete nodes
9 node shapes
Connections with 6 line styles and labels
Layout direction (top-down, left-right and more)

Work on the canvas

Click nodes on the live canvas to select them
Connect mode: click two nodes to link them
Zoom in, out and to fit

Code mode with live rendering

Edit any Mermaid type — sequence, class, state, ER, Gantt, pie, mindmap and more — as code and watch the canvas re-render as you type. Starter templates included.

Export as images

Save a diagram as PNG (2×) or SVG, or copy it as PNG to paste straight into slides or chat.

Everything you need to write Markdown

No more switching back and forth to check how your document looks — see it while you write.

Live preview

Switch between split view, editor only and preview only. In split view, the editor and preview scroll together.

Mermaid diagrams

```mermaid code blocks render as flowcharts, sequence diagrams, class diagrams and more.

KaTeX math

Inline and block math typeset cleanly with KaTeX.

Syntax highlighting

Highlighting for 15+ languages, with a copy button on every code block.

4 preview themes

GitHub Dark, GitHub Light, Notion and Paper.

PDF export and print

Export the preview to PDF or print it as it looks.

Document templates

Start fast with README, meeting notes, technical documentation, blog post, project proposal, API documentation and changelog templates.

iCloud and recent files

Save to iCloud Drive, reopen from the recent files list, or drag and drop .md files onto the window.

Screenshots

Polish your text and diagrams side by side in one window.

Mermaid flowchart source in the editor and the rendered flowchart in the preview — Mermaid flowchart — source and result side by side

Sequence and class diagrams rendered in the preview — Sequence and class diagrams

Preview showing syntax-highlighted Swift, Python and JSON code blocks — Syntax highlighting

Print dialog with page previews of the document — PDF export and print

Get the app

SSEM MarkdownEditor is sold only on the Mac App Store. It’s a one-time purchase — no subscriptions or in-app purchases — and the App Store keeps it up to date.

Price: US$0.99 (one-time purchase; local App Store pricing applies)
Distribution: Mac App Store
Requires: macOS 14 Sonoma or later
Developer: Levelupsoft Inc.

Mac App Store · US$0.99

The App Store link works once the app has been approved.

Requirements

macOS 14 Sonoma or later
An internet connection for preview rendering (Markdown, Mermaid, math, highlighting) — the rendering libraries load from the jsDelivr CDN. Your documents are never sent (details).
Saving to iCloud requires an Apple Account with iCloud Drive turned on.

See it as you write.Draw your diagrams.