Trello Card Numbers is a Chrome extension developed by hal313 that adds card numbers (IDs) to Trello cards. Trello cards have unique IDs associated with them, but they are not displayed by default. With this extension, the unique IDs of each card are visually displayed, making it easy to identify and refer to specific cards.

This extension is particularly useful for teams who use Trello for project management and collaboration. When discussing a Trello board, team members can quickly identify and reference cards using their unique IDs instead of relying solely on the card content. This helps to improve clarity and streamline communication within the team.

Trello Card Numbers is a free extension available for Chrome users. It is categorized under Browsers and falls under the subcategory of Add-ons & Tools. The source code of the extension is also available on GitHub for those interested in exploring or contributing to its development.