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.
CSS studio
Change a property in styles.css. The demo markup lives in index.html. The preview updates as you type.
styles.css
index.html
Preview updates as you type. CSS is the left pane. HTML is the middle pane.
No matching lesson.
Python, HTML, CSS, JavaScript, C, C++, Java, Kids, and the rest of the library.