The urgency of the research problem is due to the need to find new opportunities for computer-based testing, especially in the current context of the COVID-19 pandemic, when most higher education institutions operate in a distance learning environment. The aim of the article is to study the impact of retesting on the performance of students and postgraduate students on the example of studying some pedagogical disciplines in a classical university. The author used the following research methods: theoretical - in order to understand the features of computer-based testing of students in high school, formulating the conclusions of the study, etc. (analysis and synthesis, comparison, generalization, etc.); empirical – to develop didactic tests and identify indicators of initial and re-testing of students and postgraduate students (online survey, pedagogical observation); mathematical – to process the results using the computer program IBM SPSS Statistics 23. The author obtained the following specific results: according to an online survey of 1211 respondents (during 2020), almost 67% of undergraduate students, 70% of undergraduates and 83% of university students study in Moodle most disciplines during the COVID-19 pandemic. The Moodle system is most prevalent in distance learning during the COVID-19 pandemic at the university. The coefficients of internal consistency (Cronbach’s alpha) of the developed tests are equal to 0,80-0,94 for different disciplines. Students and postgraduate students took the mandatory first test at Moodle, and they also had the opportunity to retake the test of their choice. Retesting helps to improve the performance of students and postgraduate students. The average increase in test score (%) between the test and re-test was in the range of 2 -16 for various disciplines (2-14 for bachelor’s students, 11-16 for master’s students, 3-5 for postgraduate students).