How Type Fast Works

Confidence scores: how we measure each key

Confidence is the core metric Type Fast uses to measure your proficiency with each key. It represents how close you are to your target typing speed for that specific key: we divide your target time per keystroke by your actual average time. If your target is 200 ms per keystroke and you average 200 ms, your confidence is 100%. If you average 400 ms — twice as slow — your confidence is 50%.

Raw timing is noisy, though. One slow keystroke because you hesitated shouldn't tank your score. So Type Fast uses exponential smoothing: each new keystroke contributes only 10% to your running average while the previous average contributes 90%. That gives a stable measure that adjusts as your real speed changes while filtering out random outliers. Your first few presses on a key are averaged normally rather than smoothed, so one lucky fast keystroke can't stand in for a speed you can't actually sustain.

Every key falls into one of three zones: below 47% confidence is weak, 47–66% is the practicing zone, and 66% or above counts as mastered.

Crucially, your target speed isn't a fixed number — it tracks you. It's set slightly above the median speed of your own keys, so as your typing gets faster the target rises with it and "mastered" keeps meaning "fast for you now" instead of "faster than a beginner." It moves down as well as up: a genuine beginner typing at 10 WPM gets a target pitched near 10 WPM, not an adult average they have no chance of clearing yet. If you'd rather aim at a specific number, you can pin the target in Settings.

The mastery bar deliberately sits below that target rather than at it. Roughly half your keys are slower than your own median by definition, so a bar pitched at or above your median would mean your slowest fingers could never clear it however much you practised — and because a new letter only unlocks once every current letter has cleared the bar, one slow finger would freeze your progress completely. Leaving that gap is what keeps the alphabet reachable.

The focus-key system

At any moment, your weakest key becomes the focus key. The text generator then ensures that 80–100% of the words in your session contain that specific key. Struggling with R? You'll see text like "red river road rather render rare reader." That concentrated exposure accelerates improvement on your weakest link far faster than random practice would.

As soon as that key improves enough that it's no longer your weakest, focus automatically shifts to whatever is now holding you back. Your practice time is always allocated to wherever it does the most good.

How new keys are unlocked

New keys are introduced in order of how often they appear in English — starting with E, then T, A, O, I, N, S, H, R, and so on down to Z. Learning high-frequency letters first means you can type real English words much sooner, which keeps practice engaging.

And the alphabet isn't the end of it. Once every letter is mastered, the same system carries straight on into capitals, then punctuation, then numbers — one key at a time, on exactly the same gate. Most adaptive trainers stop at the 26 letters and hand you a checkbox that switches punctuation on all at once, which drops ten unfamiliar keys on you at the same moment, several of them needing Shift. Here a capital E is simply the twenty-seventh key you learn, and it arrives when you're ready for it and not before. Capitals are practised on real capitalised words, apostrophes inside real contractions, hyphens between real words, so you're learning where they actually go rather than drilling them in isolation.

The system won't add a new key until all your current keys clear three bars: 66% confidence, 90% recent accuracy, and at least five recorded attempts so the data is statistically reliable. These guardrails stop the trainer from promoting you on a few lucky keystrokes — we'd rather you solidify your foundation than rush ahead with shaky habits.

And when the last key is done, practice doesn't stop. Lessons switch to real prose — passages from public-domain books and everyday sentences — chosen for the transition you're slowest at rather than a single letter, because at that stage no individual key is your problem: the move between two of them is. The goal changes too, from covering keys to a speed ladder that keeps a next number in front of you.

Two details keep that from turning into a wall. Accuracy is measured over your recent attempts, not your whole history, so a key you struggled with early stops being held against you once you've genuinely fixed it. And the speed half of mastery is banked once you earn it: a bad session, or the bar rising as you improve, will never re-lock a letter for being a little slow. Getting stuck behind a single stubborn key is the most common complaint aimed at trainers that work this way, and it's the thing we most wanted to avoid.

What isn't banked is accuracy. If a key genuinely falls apart — not one bad session, but a sustained collapse — it's flagged for practice again, because that's a real problem worth telling you about rather than a number that drifted. Pinning the target to a specific speed in Settings also won't bank anything permanently: it changes what you're measured against, so we treat it as a goal you've set rather than as evidence, and un-pinning leaves your progress exactly as you actually earned it.

How practice text is generated

There are no pre-written sentences. Every lesson is generated from your current key set, so you never practice keys you haven't learned. The generator works in priority order: first it filters real English words that can be spelled with your current keys (with just the home row, that's words like "all," "fall," "glad," "salad," and "flask"). If too few qualify, it pulls from an extended vocabulary, then falls back to pronounceable pseudo-words built from common letter pairs like "th," "er," "in," and "an," and finally to simple key combinations.

We work hard to use real words because typing "the" thousands of times turns it into a single chunk in your muscle memory rather than three separate keystrokes. You're not just learning where keys are — you're learning how they flow together in real text.

Progress tracking and skill levels

Type Fast records smoothed timing, confidence, accuracy, attempts, and your best-ever confidence for every key, plus your WPM, accuracy, and duration for each session. It all persists in your browser's local storage — your progress is never lost between sessions, and it never leaves your device.

As you master more keys you climb through levels, counted on the 26 letters: Novice (home row), Beginner (8+ letters), Intermediate (15+), Advanced (20+), and Expert (all 26) — with the curriculum then continuing through capitals, punctuation and digits. The methodology draws on established learning science: deliberate practice (the focus-key system aims your effort at your weakest link rather than at what you already do well), progressive overload (a new key arrives only once the current ones are solid), and immediate feedback on every keystroke.

Frequently asked questions