edX is a massive open online course (MOOC) provider. It hosts online university-level courses in a wide range of disciplines to a worldwide student body, including some courses at no charge. It also conducts research into learning based on how people use its platform. EdX is a nonprofit organization and runs on the free Open edX open-source software platform.^[3]

The Massachusetts Institute of Technology and Harvard University created edX in May 2012. More than 140 schools, nonprofit organizations, and corporations offer or plan to offer courses on the edX website.^[4] As of 29 December 2018, edX has around 18 million students taking more than 2,200 courses online.^[5]

edX courses consist of weekly learning sequences. Each learning sequence is composed of short videos interspersed with interactive learning exercises, where students can immediately practice the concepts from the videos. The courses often include tutorial videos that are similar to small on-campus discussion groups, an online textbook, and an online discussion forum where students can post and review questions and comments to each other and teaching assistants. Where applicable, online laboratories are incorporated into the course. For example, in edX’s first MOOC — a circuits and electronics course — students built virtual circuits in an online lab.^[6]

EdX offers certificates of successful completion and some courses are credit-eligible. Whether or not a college or university offers credit for an online course is within the sole discretion of the school.^[7] EdX offers a variety of ways to take courses, including verified courses where students have the option to audit the course (no cost) or to work toward an edX Verified Certificate (fees vary by course). EdX also offers XSeries Certificates for completion of a bundled set of two to seven verified courses in a single subject (cost varies depending on the courses).^[8][9]