Objective: To establish reference values for the computerized cognitive test and evaluate cognitive function improvements across different age groups, we introduce the computerized Cognitive Function Test program (eCFT), specifically designed for children. We aimed to establish eCFT reference values and assess cognitive function improvements across different age groups.Methods: We included children aged 3–6 years with confirmed normal cognition based on the Korean Developmental Screening Test for Infants and Children and Kaufman Assessment Battery for Children-II. The eCFT consists of 8 subtests for visual perception, attention, memory, and executive function.Results: A total of 66 participants (36 males and 30 females) with an average age of 4.4 years participated. The age 6 group consistently outperformed both age group 3 and 4 in terms of correct responses. With regard to the completed stage, the “selective auditory stimulus” test findings were 2.0 and 3.9 for the age 3 and age 6 groups, respectively (p<0.05). The “trail-making” test findings were 1.7, 2.1, 2.6, and 2.8, respectively (between ages 3 and 6, p<0.01; between ages 4 and 6, p<0.05); moreover, the age 5 group surpassed the age 3 group (2.6 and 1.7, respectively, p<0.05).Conclusion: The eCFT is an easily accessible tool to evaluate cognitive function in young children. We introduce reference values with a cutoff range for preschool-aged children, enabling early intervention for those with cognitive impairment. Given its accessibility and relatively short evaluation time, the eCFT has potential for clinical use.