Online friendship is an inevitable phenomenon especially for young people for which Helmi et al. developed a concept and an online friendship scale with university students as their trial subject. From a developmental perspective, university students are in the early adulthood stage. With the Internet's asynchronous nature and the absence of non-verbal cues, the scale was applied to high school students in this present study. The purpose of this study was to test whether or not the online friendship scale has sound psychometric properties when applied to high school students. The subjects of this study were 214 high school students. The results of the structural equation model analysis met the goodness of fit criteria for construct validit...