There is no definitive answer to this question as it depends on the individual's individual needs and preferences. Duolingo is a great tool for learning Japanese, but it is not without its own downside. For example, some people find the learning process to be too slow or difficult. Others find the language learning tools helpful but challenging. Ultimately, the best way to find out if duolingo is good for you is to experiment with different programs and see what works best for you.