No data is collected whatsoever. Your location and speed are computed entirely on your device using the browser's GPS API and never leave it. There are no analytics, no tracking, no cookies, and no server-side processing of any kind.
Your device's GPS continuously reports your position. The browser's Geolocation API provides speed directly from the GPS signal, which is converted from m/s to km/h. No external services are involved.
tacho.click uses the Screen Wake Lock API to keep your display on. This works on Android (Chrome/Firefox) and on iOS with Safari 16.4 or later. Chrome on iOS does not support Wake Lock — to prevent the screen from sleeping, install and run the app using Safari instead.
On iOS, open the site in Safari, tap the Share button, and choose "Add to Home Screen". On Android, open the site in Chrome and tap "Install app" or "Add to Home Screen" from the browser menu.
Yes. Once loaded, the app is cached by the service worker and works without an internet connection. GPS positioning itself does not require a data connection on most devices.
GPS needs a clear view of the sky to get a fix. Indoor use or dense urban areas can delay acquisition or reduce accuracy. The accuracy figure shown at the bottom of the screen reflects the current GPS precision.