Duolingo is the most popular language-learning platform and the most downloaded education app in the world, with more than 300 million users. The Duolingo English Test is a modern language proficiency tool designed for today's international students and institutions. It offers an English proficiency score, video interview, and writing sample in an accessible, efficient, and secure testing experience. This test is accepted most of the reputed universities and colleges globally, including the education providers of the USA, UK, Australia, Canada and New Zealand. Its acceptance rate is growing day by day since. The Duolingo English Test measures English proficiency and reports scores on a scale out of 160 in 5-point increments. Test results include an overall score as well as sub scores of Literacy, Conversation, Comprehension, and Production. The overall score is not an average of the sub scores. All five scores are estimated independently and are weighted combinations of the questions that contribute to the score. Test result certificates include "Your score range" which represents the standard error of measurement (SEM). The SEM represents a range of scores within which a test taker's true score can be found. This test can be taken online anytime, anywhere and this test can be finished in an hour and can get score in two days. Like other English language tests, this test is also valid for 2 years. The cost of Duolingo English Test is US$49, which is really reasonable in comparison to IELTS, TOEFL and PTE.