The aim of this study was to determine the validity of the Internet-based ESeRNet software for the measurement of emotional music experiences by comparing the data of this study with those previously collected in a lab experiment. Participants (N = 83) listened to different music pieces online. At the same time they gave a continuous self-report about their emotional state by moving their computer-mouse in a two-dimensional emotion space and indicating chills (strong emotions accompanied by shivers down the spine or goose pimples) by clicking the mouse button. The emotional dimensions assessed were arousal and valence. Participants reported that the music pieces caused different emotional reactions that were not significantly different from the lab study using the same stimuli. Thus, the validity of this Internet-based method could be confirmed. In general, nearly all participants evaluated positively most aspects of the study — with the exception of the participation time. None of the technical parameters investigated at the participants' computers significantly affected the emotional self-report, but an influence of the self-rated concentration on arousal and chill ratings was observed. The results also show that experiments in the Web offer a promising way for emotion research and provide insights on emotions experienced when listening to music in every day life.