Live sandbox
Every lesson runs in a real, isolated browser sandbox. Write JavaScript, hit run, and watch your own code execute — no setup, no local environment to configure.
Learn by running code
Write it. Run it. Watch it happen.
Kernel is a coding-education platform built around a live browser sandbox. Every lesson ends the same way: code you wrote, running against a real test, checked the moment you hit run.
- No local setup
- Runs in your browser
- Nothing paywalled
sum.jssandbox
Waiting for you to hit Run…
Built to be used, not skimmed
No videos to half-watch. Every concept turns into code you write yourself, checked instantly against a real test.
A real curriculum, not a demo
Eight tracks from first principles through a shipped portfolio site — environment and git, fundamentals, CS theory, SQL, and full-stack TypeScript. Not one sample lesson.
Earn your way in
Finish lessons, earn coins, and unlock deeper tracks with them. Progress is visible and it's yours — nothing is paywalled behind a subscription.
Same stack as everything else
Next.js, TypeScript, Supabase — the exact tools the lessons teach are the tools this platform is built with. What you learn here is what ships in production.
First principles to shipped
Eight tracks, in order, each one unlocked by the last. These are the stages you move through.
Environment & git
Get a machine that can actually build things.
Fundamentals
JavaScript and TypeScript, written by you, run by you.
CS theory
The ideas underneath the syntax.
SQL
Data you can query, not data you hope is there.
Full-stack TypeScript
Front to back, ending in a portfolio site you shipped.
Ready to write your first line?
Sign up, open the first lesson, and run your first bit of code in under a minute.