Tab Counter is a free Firefox extension designed for effective tab management. It adds a customizable badge to the toolbar that displays the number of open tabs in the current window or across all windows. Users can configure the badge's color and text color, enhancing visibility and personalization. With options to show the count of tabs in the current window, total tabs in all windows, or total windows, it offers flexibility to suit different user preferences.

Additionally, the extension supports e10s and is optimized as a WebExtension, ensuring compatibility with Firefox 57 and later versions. Users can also opt for a clear icon mode to simplify the toolbar display. This functionality makes Tab Counter a practical tool for users seeking to streamline their browsing experience and maintain better control over their open tabs.