To evaluate scenic quality and for visual impact assessment, empirical data on landscape perception and preference are needed. Traditional means of data acquisition in perception research and public participation (on-site studies and photograph-based surveys) have serious disadvantages, for example, high costs or difficulties in participant accessibility. One possible solution for these problems is the use of the Internet for visual landscape assessment, which is described concerning its methodology and which is empirically tested in Germany regarding the influence of technical, methodological, demographic and motivational factors on dropout, response time and evaluation results. The reliability of the online survey is tested by using the test–retest-method and the split-half-method. The acquired data's validity is analysed by comparing the records gathered in the World Wide Web with data collected during an on-site survey and a traditional colour print-based questionnaire. In this study, scenic quality assessment is only influenced to a very small degree by demographic and motivational factors and fully independent of the technical and methodological configuration of the Internet questionnaire. According to the results of this study, the scenic quality categories of visual variety, beauty, visual naturalness as well as overall scenic quality can be validly recorded on the Internet, while the assessment of a landscape's peculiarity/typicality cannot be done online without further background knowledge on the landscapes presented. Limits, potentials and possible applications of online scenic quality assessment are discussed. Most of the general advantages of web experiments could be realized within the online scenic quality evaluation, which should encourage scientists and practitioners to further use and develop the method presented.