This paper describes a web application for supporting the user in the assessment of the optimal loading configuration for several carriers (i.e. trucks, containers, ship, etc.). The application has a standard form-based user-interface to insert data of the available carriers and items have to be loaded. The solution of this problem (known as Bin-Packing Problem (BPP)) is found by a specific algorithm and visualized by a 3D graphics representation inside the web page. Although some commercial applications already exist, ours runs directly on the web and offers, at the same time, an efficient and robust solver and a 3D visualization allowing the user to better understand the localization of the items inside the carrier and to interactively change some of the problem constraints directly on the 3D representation.