Digital formative assessment was considered as using digital tools and technology to apply formative assessment in the EFL classrooms. Moreover, language learners’ vocabulary retention and spelling abilities are at the heart of language learning. Therefore, the present study examined the effects of digital formative assessment in improving Iranian pre-intermediate EFL learners’ spelling achievement and vocabulary retention in Mashhad. Fifty (N=25 male & N=25 female) pre-intermediate EFL learners into two groups took part in the study. The study was an experimental study with pre-test and post-test designs. The experimental group used the Spelling Bee application in contrast to the control group. This application could present corrected words to students when they did something wrong. Moreover, the teacher gave feedback to students during tasks. The control group did their tasks on the sheet and got feedback from the teacher. KET (Key English Test) test, vocabulary, and spelling test were used as the instruments of the study. At the beginning of the study vocabulary and spelling tests were presented as a pretest to participants in both groups. The participants answered the spelling and vocabulary tests as the post-tests. After the posttest, a delayed posttest was presented to assess vocabulary retention. The obtained results revealed that the use of the digital formative assessment had no significant effect on pre-intermediate Iranian EFL learners ’spelling achievement and vocabulary retention. Administrators, EFL teachers, and EFL language learners, can take advantage of the result of the present study.