Keyword Highlighter Chrome Extension

A simple Chrome extension that allows you to highlight keywords on any webpage with custom colors.

Features

Example: Multiple keywords highlighted in different colors on a Google search page.

• Enter a keyword and a color to highlight all matching words on the current webpage.
• Add multiple keyword-color pairs without removing previous highlights.
• Highlights persist until the page is refreshed.
• Works on most websites (see Limitations below).
• Custom highlighter icon for better visual identification.

Installation

1. Clone or download this repository.
2. Open Chrome and go to chrome://extensions/.
3. Enable "Developer mode" in the top right.
4. Click "Load unpacked" and select the directory containing the extension files.

Usage

1. Click the extension icon on any webpage.
2. Enter a keyword in the text field.
3. Choose a color using the color picker.
4. Click "Highlight" or press Enter.
5. The keyword will be highlighted on the page.
6. You can add more keywords with different colors.
7. All highlights will remain until you refresh the page.

Limitations

• The extension does not work on:
  • chrome:// pages (browser settings, extensions page, etc.)
  • The Chrome Web Store (https://chrome.google.com/webstore)
  • Some internal browser pages (e.g., chrome-extension:// URLs)
  • Some error pages (e.g., chrome-error://)
• Highlights do not persist across page refreshes.
• The extension does not highlight keywords inside cross-origin iframes.

Files

• manifest.json: Configuration file for the extension.
• popup.html: The popup interface for entering keywords and colors.
• popup.js: JavaScript for the popup interface.
• content.js: Content script that handles the highlighting functionality.
• styles.css: CSS for styling the highlighted text.
• icons/highlighter_7818943.png: Custom highlighter icon for the extension.

Development

• The extension uses a custom highlighter icon located in the icons folder.
• The icon is used in multiple places:
  • Chrome toolbar extension icon
  • Extension popup window
  • Popup favicon
  • Extension management page

License

This project is open source and available under the MIT License.