From print() and lists through Django and machine learning. About 300 lessons. You can run the samples here.
Tags, forms, and layout, with a live page on the right.
Color, space, flexbox, and grid. Change a rule and the page updates.
Variables, the DOM, and events. A live page plus a console.
Pointers, structs, and files. gcc compiles in the browser.
Types, classes, and the STL. g++ compiles, then it runs.
Types, classes, and collections. javac compiles, then the JVM runs it.
Types, classes, and generics. tsc checks the file, then it runs.
Three Python levels for ages 7 to 16. Short pages, a run button, no sign-up.
Ages 7–10
Ages 11–13
Ages 14–16
Tools, prompts, review, tests, and a small project you can still explain after the AI writes it.
Learning to code: practice habits, debugging, first projects, and how to leave tutorial loops.
Python, HTML, CSS, JavaScript, C, C++, Java, and TypeScript each have an editor here. Nothing to install.
HTML studio
Edit the HTML on the left. The page on the right updates. <title> is the tab name; the heading on the page is <h1> in the body.
<title>
<h1>
Preview updates as you type. The visible name lives in <h1>, not <title>.
No matching lesson.
Python, HTML, CSS, JavaScript, C, C++, Java, Kids, and the rest of the library.