A Markdown writing tool that works right out of the box in your browser. No installation. No account. No subscription. Your words belong to you.
In the age of AI, Markdown should be simple enough.
As a Vibe Coding developer obsessed with Prompts, Agents, and Skills, I’ve used too many Markdown tools: some are too heavy, some charge subscriptions, and some sync your content to the cloud without asking. I just wanted to open a browser, type, see the layout, and take it away.
So I built this editor.
It is a browser-first toolkit: open index.html to write, everything stays local, and it works offline. It supports nearly all mainstream Agents — Codex, Claude Code, Openclaw, and more. For WeChat Official Account typesetting, switch to WeChatFormatter/.
If you also believe that in the age of AI, Markdown is the first language — welcome to use it, fork it, and star it.
- Open
index.htmlin the browser, or runnpm startto host the full toolkit locally. - Core dependencies are vendored under
public/vendor/for offline use. - Includes WeChat formatter at
WeChatFormatter/.
- Drag-and-drop import: drop files directly into the window.
- Live preview: write on the left, preview on the right in real time.
- Multiple layouts: edit + preview, edit only, or preview only.
- Source mode: edit raw Markdown directly on the right side.
- Draggable split: adjust the editor/preview ratio; position is remembered.
| Feature | Description |
|---|---|
| Headings | Quick H1-H6 insertion |
| Text styles | Bold, italic, underline, strikethrough, superscript, subscript |
| Lists | Unordered, ordered, and task lists |
| Quotes & code | Blockquotes, inline code, fenced code blocks |
| Links & images | URL insertion and local image Base64 embedding |
| Tables | Visual 8×8 table picker |
| Find & replace | Find next, replace, replace all |
Powered by i18n.js: Simplified Chinese, Traditional Chinese, English, Japanese, Korean, Spanish, French, German, Russian, Portuguese.
Language preference is persisted to localStorage.
- One-click theme switching with automatic persistence.
- All colors use CSS variables, making customization easy.
- Auto-saves content to browser
localStorageevery 500ms. - Content, filename, split ratio, collapsed states, theme, and language all survive page refresh.
| Format | Description |
|---|---|
.md |
Raw Markdown file |
.html |
Standalone HTML file |
.doc |
Word document (opens directly in Office) |
.pdf |
Browser print-to-PDF |
.png |
Long-image export with 9:16, 4:5, 3:4, 1:1, 16:9 ratios for social sharing |
| Shortcut | Action |
|---|---|
Ctrl + S |
Save |
Ctrl + Z |
Undo |
Ctrl + Y / Ctrl + Shift + Z |
Redo |
Ctrl + B |
Bold |
Ctrl + I |
Italic |
Ctrl + U |
Underline |
Ctrl + K |
Insert link |
Ctrl + Shift + K |
Insert image |
Ctrl + F |
Find & replace |
Tab |
Insert 4-space indent |
- Pure native frontend: HTML5 + CSS3 + Vanilla JavaScript, no framework.
- Markdown rendering:
marked.js - Math:
KaTeX($...$inline,$$...$$block) - Diagrams:
Mermaid 10(mind maps and flowcharts) - Image export:
dom-to-image-more - WeChat typesetting:
WeChatFormatter/(inline-style HTML for Official Accounts) - Local proxy:
Python 3(optional, for webpage-to-Markdown)
┌─────────────────────────────────────────────────────────────┐
│ index.html │
│ ┌──────────────┐ ┌──────────────┐ │
│ │ Editor │ sync │ Preview │ │
│ │ (textarea) │ ──────▶ │ (marked.js) │ │
│ └──────────────┘ └──────────────┘ │
│ │ │ │
│ ▼ ▼ │
│ localStorage KaTeX / Mermaid │
└─────────────────────────────────────────────────────────────┘
│
┌───────────────┴───────────────┐
▼ ▼
WeChatFormatter/ (WeChat) web-to-md-proxy.py
.
├── index.html # Markdown editor (main)
├── i18n.js # i18n dictionary (10 languages)
├── server.js # Unified local static server
├── public/ # Editor CSS / JS / vendor libs
├── WeChatFormatter/ # WeChat Official Account formatter
│ ├── index.html
│ ├── app.js
│ ├── config/
│ └── utils/
├── scripts/ # build / deploy
└── README.md
- mdEditor: https://www.zybkpro.top/mdEditor/
- WeChatFormatter: https://www.zybkpro.top/WeChatFormatter/
npm startThen open:
- Landing: http://localhost:3000/index/
- Editor: http://localhost:3000/mdEditor/
- WeChat formatter: http://localhost:3000/WeChatFormatter/
Or open mdEditor/index.html / WeChatFormatter/index.html directly in the browser.
# Install requests (optional, recommended)
pip install requests
# Start the proxy
python web-to-md-proxy.py
# Default port 8765
# Check "Use local proxy" in the editor
This project started from my own need for a simple writing tool, but I believe it can be better.
New features, bug fixes, UI improvements, language additions, and documentation improvements are all welcome:
- Fork the repository
- Create your feature branch:
git checkout -b feature/AmazingFeature - Commit your changes:
git commit -m 'Add some AmazingFeature' - Push to the branch:
git push origin feature/AmazingFeature - Open a Pull Request
This project is licensed under the MIT License.
You are free to use, modify, and distribute. For commercial use, please obtain authorization. I only hope that one quiet afternoon, when you write something you are truly satisfied with, you might remember where this little tool began.