DeMarkup

A Chrome extension that converts any webpage into clean, well-structured Markdown and copies it to your clipboard.

Download latest release

Features

• One-click conversion — click the icon or press Ctrl+Shift+M / Cmd+Shift+M
• Smart content extraction — pulls the main content, strips nav, ads, and clutter
• Full page mode — toggle to convert the entire page instead
• Selection support — right-click to convert just highlighted text
• Download as .md — save Markdown files named after the page
• Word/character/token counts — useful for LLM context budgeting
• Copy for LLM mode — adds page title and URL as context, strips images and noise
• YAML front matter — optional metadata header
• Configurable — bullet style, heading style, link style
• Debug logging — built-in log capture with export for bug reports
• Privacy-first — no API calls, no tracking, everything runs locally

Install

Chrome Web Store (recommended)

Coming soon.

Load unpacked (development)

1. Clone this repo
2. Open chrome://extensions/ in Chrome
3. Enable Developer mode (top right)
4. Click Load unpacked and select the demarkup/ folder
5. Pin the extension to your toolbar

Usage

• Click the icon to open the popup, then click "Copy as Markdown" or "Download .md"
• Keyboard shortcut: Ctrl+Shift+M (Windows/Linux) or Cmd+Shift+M (Mac)
• Right-click any page for "Copy page as Markdown" or select text and right-click for "Copy selection as Markdown"

Settings

Click the gear icon in the popup or go to the extension's options page:

• YAML front matter — prepend title, URL, and date
• LLM mode — add context header for pasting into LLMs
• Bullet style — -, *, or +
• Heading style — ATX (# Heading) or Setext (underline)
• Link style — inline or reference

Bug Reports

If something doesn't convert correctly on a particular page:

1. Open the extension's Settings page
2. Click Export Logs to download a JSON log file
3. Open a bug report and attach the log file

Logs include conversion events, errors, and page metadata — no personal content is captured.

Project Structure

demarkup/
├── background/
│   └── service-worker.js    # Context menus, shortcuts, message routing
├── content/
│   └── content.js           # HTML extraction, cleanup, Turndown conversion
├── popup/
│   ├── popup.html           # Extension popup UI
│   ├── popup.js             # Copy/download actions, mode toggle
│   └── popup.css
├── options/
│   ├── options.html          # Settings page
│   ├── options.js            # Settings persistence
│   └── options.css
├── lib/
│   ├── turndown.js           # Vendored Turndown.js (do not edit)
│   ├── turndown-plugin-gfm.js # Vendored GFM plugin (do not edit)
│   └── logger.js             # Debug logging with export
├── icons/
│   ├── icon-16.png
│   ├── icon-48.png
│   └── icon-128.png
└── manifest.json

Tech

• Manifest V3
• Turndown.js for HTML-to-Markdown conversion
• turndown-plugin-gfm for tables and strikethrough
• No build step — plain JS, HTML, CSS loaded directly by Chrome
• No external API calls — everything runs in-browser
• Permissions: activeTab, clipboardWrite, storage, contextMenus

Contributing

Contributions are welcome. See CONTRIBUTING.md for setup and guidelines.

License

MIT