This thesis contrasts two of the most popular language teaching applications: Memrise and Duolingo which are quite different characteristically, but share the value of being prosperous and popular in teaching languages worldwide. In this dissertation the statement that both Duolingo and Memrise have a clearly distinguishable utilization of preferred vocabulary learning strategy is proposed; Duolingo mainly uses the characteristics of cognitive strategies with using the words in context, making patterns and making the learners practice vocabulary through drills, however Memrise, as its name tells us usually makes use of various memory strategies, for example making mental linkages, using pictures and related words, and so on to help its users to learn the words of the target language as rapidly as possible. Since the number of researches done to compare strategies and such applications is very limited, a small-scale online survey was conducted to measure the overlap between which vocabulary learning strategies are preferred by the learners and which app (Memrise and Duolingo) they feel to be more successful in teaching vocabulary.