About Car Speed Test
Welcome to Car Speed Test, a free browser-based GPS speedometer that turns any phone, tablet, or laptop into a real-time vehicle speed tracker. Whether you're a driver checking your car's speedometer accuracy, a cyclist tracking a ride, or a traveler curious how fast your train is moving, this tool gives you a clean, accurate readout — no app install, no signup, no fee.
Our mission is simple: build a speedometer that's as useful as a dedicated device, but available instantly in any modern web browser. Everything runs locally on your device, your GPS data never leaves your hardware, and the interface is designed to be readable at a glance.
What This Tool Does
- Real-time speed display in km/h, mph, knots, or m/s.
- Analog and digital speedometers — pick the look you prefer, or use both.
- Top, average, distance, and duration stats for every trip.
- GPS accuracy indicator so you always know how reliable the reading is.
- Customizable themes with five color options and a dark mode.
- Mobile-first design with large, glanceable numbers and big buttons.
How It Works
Car Speed Test uses the browser's built-in Geolocation API to read GPS data directly from your device. As you move, the API reports your position and (on most devices) a calculated speed. Where the device doesn't report speed directly, we calculate it from successive position samples using the great-circle distance formula.
Because all calculations happen in your browser, the tool works as long as your device has a GPS fix — even if you lose internet for a while after the page has loaded.
Who Is It For?
- Drivers verifying their car's built-in speedometer accuracy.
- Cyclists, runners, and skaters tracking ride speed and distance.
- Boaters and pilots needing a quick knots readout.
- Passengers curious about train, bus, or plane speed.
- Driving instructors demonstrating speed in different units.
Privacy First
We don't store your GPS coordinates, route history, or any personally identifying location data on our servers. The speedometer is a purely client-side tool. Read our privacy policy for the full details.
Ready to try it? Open the speedometer and tap Start Tracking.