DeMarkup

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

Install from the Chrome Web Store · 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)

Install DeMarkup from the Chrome Web Store, then pin the extension to your toolbar.

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, scripting

Privacy

DeMarkup collects nothing. No analytics, no telemetry, no network requests — conversion happens entirely in your browser, and page content goes only to your clipboard or a file you download.

See PRIVACY.md for the full policy.

Contributing

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

License

MIT

The bundled fonts (DM Sans, Instrument Serif) are redistributed under the SIL Open Font License — see fonts/LICENSE.md.