About Handwashing Coach

Handwashing Coach teaches the six handwashing steps from the World Health Organization with a 20-second scrub timer. The camera watches your hands, checks your hand shape and your rubbing step by step, and names one mistake at a time so you can fix it. Made for kids, and for grown-ups who supervise them. Available in English, French, Spanish and Japanese.

How it works

• Hand tracking runs on your device, in your browser, using the MediaPipe hand model that ships with the app. It finds 21 points on each hand (fingertips, knuckles, wrist) from the camera picture. The picture itself never leaves your device.
• Each step has two checks: the hand shape (are your hands in the right position?) and the movement (are you actually rubbing?). Both must pass for the scrub timer to count.
• The 20-second timer is split across the six steps: each step needs about 3.3 seconds of good scrubbing before the next one starts. The timer ring shows your progress, and a chime and confetti celebrate each finished step.
• One named hint at a time: when the shape is wrong you get one specific fix ("Straighten your fingers"), and when the shape is right but you are not moving you get one specific prompt ("Now rub your hands against each other, back and forth").
• Two-sided steps: the thumb twist and the fingertip circles must be done on both sides ("now the other thumb") before the step counts as finished.
• Test mode shuffles the six steps, hides the "how to do it" instructions until you ask for them, and scores how many steps you pass without a hint.
• Progress: points, levels, day streaks and badges track practice on the home page. Everything is stored only in this browser on this device.

The hints

• "Bring your hands together": the step needs both hands touching. Get them close.
• "Straighten your fingers": this step needs open, flat hands. Uncurl them.
• "Turn your palms to face each other": palm-to-palm steps need the palms facing.
• "Lay one palm on the BACK of the other hand": the palm-over-back step needs the palm on the back, not palm to palm.
• "Spread your fingers and slot them between the fingers": lacing steps need the fingers interlaced.
• "Curl your fingers and hook them together": the finger-hooks step needs curled fingers hooked into each other.
• "Wrap one hand around the other thumb": make a loose fist around the other thumb and twist.
• "Pinch all your fingertips together": the last step needs the fingertips bunched, rubbing little circles in the other palm.
• "Now rub / twist / make circles": your shape is right, but the app sees no scrubbing movement yet. Keep going for the full count.

When a step is done, a chime and confetti celebrate it. Wrong answers always name the fix, never just a score.

The six steps

• 1. Palm to palm: rub your palms together, fingers straight and together.
• 2. Palm over back: lay one palm on the back of the other hand, fingers between fingers, and rub. Then swap hands.
• 3. Fingers laced: palm to palm again, but spread your fingers and slide them between each other. Rub up and down.
• 4. Finger hooks: curl your fingers and hook them into each other, backs of fingers in the other palm. Rub side to side.
• 5. Thumb twist: wrap one hand around the other thumb and twist. Then do the other thumb.
• 6. Fingertip circles: pinch your fingertips together and rub them in little circles in the other palm. Then swap.

These are the WHO's six hand-rubbing steps. Wet your hands and add soap before you start; rinse with water and dry your hands when you finish.

Resources: learn the real thing

For real instruction, learn from the WHO handwashing guidance above. The app checks shape and movement; it cannot tell whether hands are actually clean.

These links open other websites in a new tab. Handwashing Coach isn't affiliated with any of them and sends them nothing.

Privacy

• The camera picture never leaves your device. Hand tracking runs in your browser on a model that ships with the app. Each frame is analysed and discarded. Nothing is recorded, uploaded, shared or stored.
• No accounts, ads, cookies, analytics or trackers. The app loads nothing from other websites, and a security policy blocks connections anywhere else.
• Stored on your device only: steps passed, points, badges, day streaks, settings and whether you have seen the welcome message, in your browser's local storage. Delete it with Offline proof → Delete all my data, Settings → Clear progress, or your browser's site settings.
• The camera is only on during a wash session after you press Start washing. It turns off when you go home, press Turn off, or switch to another tab.
• Hosting: like any website, the server that delivers the app's files may keep standard technical logs of those downloads. The app itself sends nothing. Full privacy page

Disclaimer

• This is a home practice tool, not a teacher, therapist or safety device. Everything runs on your device: no video, audio or images are sent anywhere. Feedback is automatic and can be wrong. For real instruction, learn from the WHO handwashing guidance (linked on the Resources page).
• The app checks hand shape and movement with simple rules. It cannot tell whether hands are clean, and wet, soapy or overlapping hands are hard for any camera.
• Grown-ups: supervise young children during real handwashing. This app is practice; soap, water and rinsing do the cleaning.
• The app is provided “as is”, without warranty of any kind.

Accessibility

• Hints and step names are announced to screen readers, and every control works with a keyboard. Each step also shows a written "how to do it" line, so the camera feedback is never the only way to know what to do.
• Animations follow your device's "reduce motion" setting, and chimes and confetti can be turned off in Settings.

Credits

• The six handwashing steps are the World Health Organization's hand-rubbing technique. Hand tracking uses the MediaPipe Hand Landmarker model by Google, vendored with the app (see THIRD_PARTY_NOTICES.md). Step rules, the timer, tests and all text in English, French, Spanish and Japanese are original code and content written for this app.
• Built with the on-device coach pattern from the Little Hands and Tai Chi Coach apps.

Handwashing Coach version 1.0.0