Learn frontend by seeing the code run.
Free, interactive courses where every example runs, every value can be stepped through, and Tuto, an AI tutor, sits beside every lesson.
Free No sign-up to start Beginner to expert
- 343JavaScript lessons
- 180algorithms explained
- 751practice problems
- 7languages to code in
Courses
Pick a path. Each one starts from zero and goes all the way to expert.
JavaScript
The complete path, from your first line of code to closures, the event loop, the DOM, and how engines run it.
- 343 lessons
- 12 stages
- Beginner to expert
Data structures & algorithms
Every algorithm explained step by step with a picture you can play, and problems to solve in seven languages.
- 180 algorithms
- 751 problems
- 7 languages
- TypeScript
- React
- Angular
- Vue
- Next.js
- HTML
- CSS
- Node.js
- Frontend system design
- Web performance
Not another wall of text
Every lesson is built so you understand it, not just read it.
Step through real code
Every example runs. Move one line at a time and watch each value change, so you see what JavaScript does instead of guessing.
A tutor that knows the lesson
Ask Tuto about any line, error, or idea. On practice problems it gives hints, never the answer, so you still solve it yourself.
Practice right where you learn
Edit and run every example, then solve problems in a playground with tests, in JavaScript or six other languages.
Lessons you can trust
Automated tests run every lesson's code and check the outputs, quiz answers, and exercises it shows before it's published.
The JavaScript path
12 stages, in order, from your first line of code to how engines run it. See every lesson
Free tools
Who writes this
Shrikanth PS
More than nine years of frontend engineering at several top tech companies, shared one concept at a time, in plain language, with code you can run and change until the idea clicks.
Your first lesson takes about 10 minutes.
No account, no install. Open it and press Run.