The paper discusses the problem of websites and cartographic presentations usability (quality, efficiency and accessibility). The opening sections comprise brief introduction into websites usability, site design and user centered design. The role of interactivity, hypermedia and multimedia in digital cartographic environment is explained. The main part of the paper deals with general principles for website interface design. They are for example visibility of system status, matching between system and the real world, consistency and standards, error prevention, flexibility and efficiency of use and so on. Considering these heuristic principles the use of maps and cartographic visualisation is discussed. It provides support for information preparation, aesthetic graphic presentation and framework limitations solutions. The paper also presents some technical aspects of editing usable maps on the WWW.