The purpose of this study is to investigate the usability of interactive videos for developing spatial skills of students in geometric solids. For this purpose, it is aimed (1) to specify crucial steps for developing such videos viewed by web browsers, (2) to examine the interactive environment, which were developed in accordance with the learning outcomes of geometric solids in Ministry of National Education elementary school mathematics curriculum, by experts based on Nielsen's heuristics and (3) to point out the opinions for usability of such videos in teaching of geometry. Experts evaluated the developmental process in which the exploratory research method was used. Accordingly, heuristic evaluation was made by mathematics education experts based on Nielsen heuristics to identify the usability of the video. The data obtained from the interviews were qualitatively analyzed and matched with Nielsen heuristics. The codes obtained in terms of the contribution of the interactive video to the teaching process and the student are presented in the themes and categories. At the end of the evaluation, the experts agreed on the usability of interactive videos in teaching of geometry for developing spatial skills and showed positive attitude towards the development of such videos. For further developments, it is suggested to provide such videos in students' familiar media and interfaces, place interactive question-answer environment and associate the content of videos with daily life.