CoPen is a free Chrome extension designed to streamline web page design feedback and collaboration. It allows users to add comments anywhere on a web page, making it ideal for design reviews and project discussions. Key features include intuitive comment placement, adjustable comment positioning, and the ability to engage in threaded discussions for effective communication among team members. The side drawer displays all comments for easy navigation, enabling users to jump to specific sections quickly.

In addition to its collaborative tools, CoPen automatically saves comments locally and supports export and import in JSON format. Users can also customize the interface to suit their preferences, placing the comment dock in any corner of the screen. With a focus on privacy, all data remains on the user's device, ensuring security. CoPen is particularly beneficial for web designers, front-end developers, and project managers looking to enhance their design review processes.