Tracks
Four languages. One habit: write.
Each track starts at absolute zero and builds in small, ordered steps. A lesson only ever asks what earlier lessons taught.
Honest checking
Strict where the language is strict. Forgiving where it isn't.
Nothing you type is compiled or run. Your code is compared against the lesson's answer with rules that match what the lesson teaches — so a stray space never fails you, and a wrong capital never slips through when capitals are the point.
Extra spaces, blank lines and quote style — print( "hi" ) is still print("hi").
Capitals inside your messages — print("Hi") passes when the answer is print("hi").
Keyword case — PRINT("hi") fails, because Python really does reject it.
Lessons marked Strict check every character and space — indentation and case lessons only work that way.
Curriculum
Small steps, in the right order.
The first lessons of each track. Level 1 assumes you have never seen code. By the level boss you are combining ideas on your own.
Free to start
Your first line of code is five minutes away.
Sign in with an email code. No password, no card, no install.