Domain Border Highlighter is a Chrome extension designed to help users easily identify active websites through customizable borders. Users can assign specific colors and thicknesses to borders for different domains, making it particularly useful for distinguishing between development, testing, and production environments. The extension ensures that personal preferences or team rules can be effectively implemented by allowing users to save their settings for later use.

The extension features real-time application of settings, meaning any changes made are instantly reflected across all open tabs. Additionally, it employs an overlay method that adds borders without altering the page layout. Users can manage their settings easily through a dedicated popup, which displays all saved domains for quick edits or deletions. The extension also syncs with the Chrome account, ensuring that users maintain their visual recognition rules across different devices.