Quizlet is a multi-national American company that provides tools for studying and learning. Quizlet was founded in October 2005 by Andrew Sutherland, who at the time was a 15-year old student, and released to the public in January 2007. Quizlet's primary products include digital flash cards, matching games, practice electronic assessments, and live quizzes. In 2017, 1 in 2 high school students used Quizlet. As of December 2021, Quizlet has over 500 million user-generated flashcard sets and more than 60 million active users.