KeepDown

A Chrome extension that adds real-time Markdown preview to Google Keep notes. Write your notes in Markdown and see them rendered instantly alongside your text.

Features

• Real-time side-by-side Markdown preview
• Three Markdown view modes: Editor / Editor and Preview / Preview
• Optional editor-to-preview scroll sync in Editor and Preview mode
• Built on top of micromark
  • 100% CommonMark compliant
  • GitHub Flavored Markdown supported
  • LaTeX math expressions supported
• Optional paragraph soft line break preservation for command snippets and plain text lists
• Per-note view mode persistence — each note remembers its last selected mode
• Draggable resize handle for adjusting modal width on the fly
• System, Dark, and Light preview themes

Markdown View Modes

A three-button toggle is added next to Keep's "Pin note" button inside the modal:

• Editor — Default Google Keep editing view, no Markdown preview
• Editor and Preview — Side-by-side editor and rendered Markdown preview, with optional preview scrolling that follows the editor
• Preview — Rendered Markdown only, editor hidden

The active mode is saved per-note, so each note remembers its own view preference.

Extension Settings

Click the extension icon to open the settings popup:

• Markdown by default — Toggle whether new notes open in Split mode or Editor mode
• Sync editor scroll — Toggle whether the preview follows editor scrolling in Split mode; enabled by default
• Preview theme — Follow Google Keep's current appearance by default, falling back to the system appearance, or choose a fixed Dark or Light theme with a live preview sample
• Preserve soft line breaks — Keep single line breaks visible inside normal paragraphs; disabled by default to preserve standard CommonMark rendering
• Editor width — Slider (600px–1600px) to control modal width in Editor-only mode
• Editor and Preview width — Slider (50%–95%) to control modal width in Split mode
• Preview width — Slider (50%–95%) to control modal width in Preview mode
• Reset — Restore all settings to defaults

All changes sync instantly to any open Keep tab without reloading.

Chrome Extension Permissions

This extension uses minimal permissions:

Content Script Host Access

• The extension only runs on https://keep.google.com/* to:

  1. Add the Markdown preview panel to the note editor
  2. Listen for changes in the note content to update the preview
  3. Apply custom styling for the preview panel

  The extension does not:

  • Collect or transmit any note content
  • Access any Google account information
  • Modify or store your notes
  • Make any network requests

  All processing is done locally in your browser.

storage Permission

• Used to save your preferences (such as note modal widths, preview theme, scroll sync, and paragraph line break behavior) between browser sessions. This ensures your customized settings persist after closing and reopening your browser.

Getting Started

1. Clone this repository
2. Install dependencies:

npm install

3. Build the extension:

npm run dev

4. Load the extension into Chrome:
   • Open Chrome and navigate to chrome://extensions/
   • Enable "Developer mode" in the top right
   • Click "Load unpacked"
   • Select the extension directory
   • Click "Add"

Building for Production

npm run build

Create distribution ZIP (for Chrome Web Store):

zip -r dist-zip/keepdown.zip extension