Assessments of developmental spelling, also called spelling inventories, are commonly used to understand students' orthographic knowledge (i.e., knowledge of how written words work) and to determine their stages of spelling and reading development. The information generated by these assessments is used to inform teachers' grouping practices and instructional priorities. While relatively easy to administer, developmental spelling assessments can be time-consuming to score and are susceptible to human error in both the scoring and the interpretation of results. The purpose of this study is to develop and validate an online version of a commonly used spelling inventory, making the assessment more efficient and accessible and the results more reliable for teachers and scholars alike. Implications for practice and directions for further research are discussed.