Brilliant

Brilliant's defining bet is that you learn math and science by doing rather than watching, and its interface is built almost entirely from interactive widgets. A lesson rarely just tells you a concept; it hands you a draggable diagram, a tappable simulation, or a multiple-choice step that will not advance until you reason it out. Wrong answers trigger an explanation rather than a penalty, keeping the loop low-stakes and exploratory. Courses are short, sequential, and visually clean, with a daily-problem habit hook on the side. The tradeoff of this hands-on density is pace: deeply interactive lessons take real cognitive effort and cannot be skimmed, so progress feels slower than a video course even when comprehension runs deeper. The mobile layout occasionally cramps the richer diagrams.