How keystroke works

The adaptive loop

Every lesson is generated for you. As you type, keystroke measures your speed and accuracy per letter. After each lesson it finds your weakest letter — the focus letter (starred in the readout, ringed red on the keyboard) — and generates the next lesson with that letter appearing more often. Type → measure → drill the weakest → repeat.

Why the words look invented

Lessons are pronounceable non-words built only from the letters you've unlocked. That's deliberate: real words let you lean on prediction and vocabulary; invented ones train pure muscle memory for every letter transition. As you unlock more letters the words get richer.

Unlocking letters

You start with the 8 most frequent letters of English. Each letter has a confidence score = your speed × your accuracy on it, measured against your goal speed (set in settings). When every unlocked letter reaches 1.0, the next letter joins — in frequency order, up to all 26. Unlocks are based on your best performance, so they don't regress on an off day.

The colors

• grey — not unlocked yet (or not typed yet)
• red — below 0.8 — this is what the trainer drills
• amber — 0.8–1.0 — almost there
• green — 1.0+ — at your goal (unlocks count your best run, so a bad day can’t re-lock a letter)

The same colors appear on the on-screen keyboard while you practice and on the heatmap in progress.

Corrections & honest accuracy

By default Backspace is off: a missed key must be retyped where it happened, so your accuracy number is honest and your hands learn the correction motion. Prefer normal editing? Turn on allow corrections in settings. Also: lessons are lowercase only — if everything suddenly fails, check Caps Lock.

Practice vs the typing test

The trainer at practice builds skill with adaptive lessons; the typing test measures your current speed on a standardized timed test (15/30/60s of common English words) — that's the number to compare with friends.

Do I need an account?

No — everything works anonymously, with progress saved in your browser. Signing in (free) saves progress to your account across devices and ranks you on the leaderboard — anonymously by default. See the privacy policy.