Cardmarket Assistant is a Firefox extension designed to enhance the user experience for card collectors and traders. This subscription-based tool offers a variety of features aimed at simplifying the buying and selling process on Cardmarket. Users can easily access detailed information about their card collections, including which printings they own and their locations within their ManaBox collection. The extension also automatically fills out selling forms and calculates optimal pricing, making it a valuable asset for both casual and serious collectors.

In addition to its selling features, Cardmarket Assistant provides playability metrics for cards, allowing users to make informed purchasing decisions. The tool also includes options to filter out cards based on legality for different formats and assess the value of offers at a glance. With capabilities to import and export Wants-Lists in .csv format, managing collections becomes more efficient. Overall, Cardmarket Assistant serves as a comprehensive solution for card enthusiasts looking to optimize their Cardmarket interactions.