Crash Course is a YouTube educational channel producing fast-paced video series on subjects such as history, biology, chemistry and literature for students and curious viewers.
Brilliant is an interactive learning platform offering bite-sized, problem-solving courses in maths, science, computer science and data, built around hands-on practice.
BYJU'S is an Indian ed-tech company that offers online learning apps and tutoring for school students, with animated lessons in maths and science, and test preparation.
Khan Academy is a non-profit education organisation offering free lessons, practice exercises and videos in maths, science and other subjects for learners of all ages worldwide.