An AI tutor that never does it for you.It teaches. The tests grade. You pass it yourself.
Most AI “help” just writes the answer — and you learn nothing. Here the tutor coaches, a static hint ladder backs it up, and pass/fail comes from real tests running in your browser. The AI has no say in your grade. Try an exercise below, no signup.
The demo exercise is warming up — check back in a moment.
The AI never grades you
Your code runs against real tests, right in your browser. Pass/fail is deterministic — no model deciding your work is “close enough.”
Help that teaches, not answers that leak
In our own measurements, most tutor interactions are followed by the learner passing the exercise themselves within 3 tries — help that teaches, not answers that leak.
A tutor that knows where you are
Struggle and the game diagnoses why, then builds targeted practice around exactly that gap. Fly through and it moves you up. The course shapes itself to you.
Get unstuck without getting spoiled.
Meet your tutor — freeEvery learner gets a free daily tutor allowance, and static hints are always free. Max removes the cap — the exercises themselves are free forever.