A digital literacy scale (DLS) was developed to assess the digital literacy levels of secondary school students. The validity and reliability of the DLS were evaluated using the Rasch model. The DLS was initially composed of 25 items, but 5 items were removed based on expert opinions, leaving 20 items. The content validity of the DLS was ensured through expert evaluation, while construct validity was assessed using the Rasch model. The DLS was analyzed using exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) to determine its unidimensionality and internal consistency. The results showed that the DLS met the necessary statistical criteria for a valid and reliable measurement tool. The DLS demonstrated strong internal consistency, with a Cronbach's Alpha coefficient of 0.982. The reliability analysis also confirmed that the DLS had high reliability, with correlation coefficients between the two halves of the scale exceeding 0.896. The DLS was found to be unidimensional, with a high factor loading for each item. The results of the CFA confirmed the construct validity of the DLS, with all items loading significantly on the latent factor. The DLS was also found to have good measurement invariance across different groups. Overall, the DLS was validated as a reliable and valid tool for assessing the digital literacy levels of secondary school students.A digital literacy scale (DLS) was developed to assess the digital literacy levels of secondary school students. The validity and reliability of the DLS were evaluated using the Rasch model. The DLS was initially composed of 25 items, but 5 items were removed based on expert opinions, leaving 20 items. The content validity of the DLS was ensured through expert evaluation, while construct validity was assessed using the Rasch model. The DLS was analyzed using exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) to determine its unidimensionality and internal consistency. The results showed that the DLS met the necessary statistical criteria for a valid and reliable measurement tool. The DLS demonstrated strong internal consistency, with a Cronbach's Alpha coefficient of 0.982. The reliability analysis also confirmed that the DLS had high reliability, with correlation coefficients between the two halves of the scale exceeding 0.896. The DLS was found to be unidimensional, with a high factor loading for each item. The results of the CFA confirmed the construct validity of the DLS, with all items loading significantly on the latent factor. The DLS was also found to have good measurement invariance across different groups. Overall, the DLS was validated as a reliable and valid tool for assessing the digital literacy levels of secondary school students.