Build the weird stuff you actually want to build.
Drag blocks, read the real JavaScript and Python they compile to,
and ship apps, games, and hardware projects that don't look like homework.
Categories
Three steps. Then you're on your own.
The hand-holding ends at step three. After that it's just you, a blank file, and 300+ blocks.
Snap blocks together
Every block is a real thing the computer can do. Sensors, math, sprites, HTTP requests. Drag, drop, connect.
See what it actually is
Every block is also real code. Toggle the pane — your blocks are already JavaScript or Python. The abstraction leaks on purpose.
on('click', () => {
if (x < 0) bounce()
})
Put it on the internet
Hit run — it runs. Hit share — it's a URL. Hit deploy — it's on your phone.
All of this, on day one.
No paywalls on the thing you actually need right now.
Blocks
From print to train classifier. Every block is a real primitive.
Challenges
Progressive puzzles that teach a concept and then ask you to break it.
Multiplayer
Rooms, shared state, presence. Build with a friend in the same file.
Game Engine
Sprites, physics, tilemaps. The boring parts are written. Go make Celeste.
AI & Vision
Webcam, pose, speech. Models run in the browser — your face never leaves the tab.
Hardware
micro:bit, Arduino. Flash firmware from the browser. Lights blink, motors spin.
Badges
Earned, not given. Common → Legendary. Some require you to stumble into them.
Daily Challenge
One tiny prompt, 24 hours, global leaderboard.
80+ badges. You earn them, you don't buy them.
Common ones take minutes. Legendaries take weeks — sometimes a specific time, sometimes a block combo nobody's told you about.
First Block
You connected two blocks. That's it. We're proud of you.
Signal & Noise
Built something that listens to the microphone and reacts in under 15 blocks.
Local Maxima
Shipped a project that 100 kids forked, then forked back.
???
Requirements hidden. Hint: check the terminal.
A classroom that runs itself.
Assignments auto-grade what can be auto-graded. The rest you read in ten minutes instead of an hour.
- ✓ Classrooms & rosters — join codes, student management.
- ✓ Assignments with rubrics — grade by block count, concepts used, or output.
- ✓ Student replays — scrub through how they built it, not just the result.
- ✓ Free for public schools — always. No asterisk.
Every block, free. Forever.
We don't gate the learning part. Pro unlocks creative tools you only need once you're serious.
Hacker
Everything a kid needs to learn, build, and ship real things.
- All 300+ blocks, all 23 categories
- All 141 challenges + daily challenge
- Public projects, fork & remix
- Multiplayer rooms (up to 4)
- Hardware support (micro:bit)
- Badge system, no limits
Pro Creator
For kids making bigger things.
- Everything in Free
- Private projects & rooms
- Custom block authoring
- Code Golf & Code Labs
- Sprite Editor & Level Editor
- Scratch import, PWA export
Go make something
no one asked you to.
Takes ~45 seconds. No email needed to start. Pick a username. Drag a block. See what happens.