Code Monster
Change small bits of JavaScript and watch the result instantly
Code Monster is a set of short, interactive JavaScript lessons. You follow small instructions on screen, change the code, and see the result right away. You start by drawing boxes and colors, then move on to simple animation and fractals.
Free · No login · Browser · Beginner
About Code Monster
Along the way the lessons show you variables, loops, conditionals, expressions and functions through examples. It is made for kids, but adults who have never coded can use it too. It is a first step, not a full course.
It runs in a desktop browser, ideally Chrome or Firefox, and is not designed for phones. You do not need to register. Your progress is saved in your browser, and the site works offline after it loads once. It comes from Crunchzilla by Geeky Ventures.
On Breakpoint since 23 Oct 2026.