Interactive Courses
Frontend, AI and engineering concepts, explained step by step. See how each idea works, then put it into practice at your own pace.
Free until 31 October
JavaScript Memory and Garbage Collection
Find out what keeps an object alive, why apps leak memory, and how the browser cleans up without freezing the page.
Premium
How the Browser Runs and Renders Your Code
The event loop and rendering, one step at a time. Predict any output order, and fix a page that freezes.