Khan Academy

Khan Academy is a non-profit education platform offering a full curriculum from primary mathematics through to advanced subjects, free of charge. Content is organised into courses, each broken into units with instructional videos, articles, and practice exercises. The pedagogical model is built around practice rather than video alone. Exercises are generated with randomised parameters, so a learner can attempt a skill repeatedly, and the system tracks mastery at the skill level. That data drives a dashboard showing which skills are secure and which need work. The platform is free and funded by donations, with no advertising and no paid tier for learners. Its limitation is scope and depth: it covers standard curricula well, but it does not offer the credentialing, the live instruction, or the specialised advanced content that a university programme or a paid platform provides.