Is Khan Academy Really Free

Is Khan Academy Really Free. Time after time i found myself going back to the khan academy physics videos to refresh myself on lens equations, circuits, and force diagrams. Khan academy for adult learners.

Khan Academy Review 2020 PCMag Asia
Khan Academy Review 2020 PCMag Asia from

In my view, khan academy should be used as one would (ideally) use a textbook: As a nonprofit, khan academy makes money via donations, tuition fees from its khan lab school, and compensation for its sat prep courses. 2 is khan academy really free?