Start with the most-loved learning tracks
Use version control as a collaboration tool: commit with intent, branch on purpose, merge without fear, resolve conflicts deliberately, and ship work through a pull request that a reviewer can actually read.
Output-based
Components, state and the rendering model behind React. Learn why a component is just a function, what a state snapshot really is, and how keys, effects and custom hooks fit together.
Output-based
The building blocks of every website: semantic HTML for structure and modern CSS for beauty — including Flexbox and Grid.
Output-based
Objects and references, the String and generics model, the collections framework, exceptions, the Stream API and the concurrency essentials.
Output-based
The Node runtime, its event loop, and building a JSON API with Express — pinned to Node 22 and Express 5.
Output-based
Master the essentials of Python — the world's most approachable programming language. From print statements to classes, 24 hands-on lessons with a real inline editor.
Output-based
Everything you need to go from zero to shipping
Micro-blocks: concept → example → run code → quiz → challenge. No passive video-watching.
Run Python, JavaScript, SQL and HTML in an isolated sandbox and get instant output.
Every action earns XP. Level up, keep your daily streak and climb the leaderboard.
Unlock achievements and earn verifiable, forgery-resistant certificates on completion.
A fresh mission every day: 1 lesson, 1 quiz, 1 challenge for bonus XP.
Ask questions, answer others, bookmark and earn recognition for helping learners.
A structured route from beginner to job-ready
Bite-sized lessons with interactive code.
Quizzes, challenges and a daily mission.
Calculator, weather dashboard, portfolio and more.
Complete a path and get a verifiable credential.
Public tests for practice, hidden tests for real validation
Loops, strings, arrays — build muscle memory with instant feedback.
Functions, data structures and debugging exercises.
Secure coding, SQL mastery and real-world problem solving.
Build real things — with tests and XP rewards
Collect them all
Yes — the core learning experience (courses, lessons, quizzes, challenges) is free. Premium unlocks advanced content and certificates.
Lessons, quizzes, challenges, projects and daily missions all award XP. XP drives your level and leaderboard rank — awarded by the server only.
No. The code playground runs in an isolated browser sandbox — Python (WASM), JavaScript (worker) and SQL all work in the browser.
Yes. Every certificate has a unique ID and a public verification URL that anyone can check.