Khan Academy

Khan Academy is a free online learning platform that offers structured courses across a wide range of subjects, including mathematics, science, computing, economics, history, and test preparation. The platform provides thousands of instructional videos, interactive exercises, and practice problems designed to support learners from early elementary school through college-level content. Lessons are organized into clear learning pathways with sequenced units, allowing users to progress step-by-step through topics such as arithmetic, algebra, calculus, biology, physics, and more.

A core feature is its adaptive practice system, which adjusts difficulty based on performance and highlights areas where additional review is needed. Learners receive instant feedback, detailed solution explanations, and progress tracking via dashboards. Teachers and parents can create classes, assign specific skills or units, monitor student activity, and access reports on mastery levels and time spent.