Khan Academy

Khan Academy is a nonprofit educational organization that provides free, world-class online lessons, practice exercises, and instructional videos across subjects including math, science, economics, computing, and test prep. Its platform offers a personalized learning dashboard, mastery-based practice, and teacher/classroom tools to support students K–12 and beyond. Content is available in many languages and aligned to standards, and the site is funded primarily by donations and grants. Educators and learners use Khan Academy for scalable, self-paced instruction and formative assessment.