Written by Muneeb Rana · Last updated 26 October 2026
Quick answer: This online speedometer uses your browser's Geolocation API to read your position and, where the device provides it, your speed, then shows it in MPH or KM/H. Allow location when asked, step outside or sit by a window, and wait a few seconds. Nothing is uploaded; the calculation runs in your browser.
TL;DR
- Runs in the browser; no app or account.
- Needs location permission and a GPS-equipped device.
- Laptops without GPS give poor or no speed.
- Readings update about once a second.
- For trips, HUD and history, use the app.
How to use the online speedometer
- Press Start and allow location access.
- Choose MPH or KM/H.
- Keep the page open and the screen on.
- Read the big number; the small text shows the reported accuracy in metres. If the speed shows a dash, your device has not delivered a speed value yet; give it time outdoors.
How it works
Browsers expose a coords.speed value in metres per second when the device can estimate it. If it is missing, the tool falls back to distance between two fixes divided by the time between them, ignoring fixes with poor accuracy. That fallback is noisier, which is why phones outdoors work far better than laptops on Wi-Fi location.
Accuracy you can expect
On a phone outdoors, close to app-level accuracy. GPS.gov puts typical smartphone position accuracy at about 4.9 m under open sky. Indoors, on Wi-Fi-only devices, or in city canyons the speed may jump or read zero. See GPS speedometer accuracy.
Online speedometer vs the app
The browser tool is good for a quick check as a passenger or on a walk. The Speedometer PRO app adds HUD mode, analog and digital meters, trip stats with history, a compass and a map, and it keeps running more reliably than a browser tab, which the phone may suspend.
Privacy
Your location never leaves the page. Nothing is stored except your unit preference in local storage.
Speed conversion quick table
Use this when you only have one unit on the dash.
| MPH | KM/H |
|---|---|
| 10 | 16.1 |
| 20 | 32.2 |
| 30 | 48.3 |
| 40 | 64.4 |
| 50 | 80.5 |
| 60 | 96.6 |
| 70 | 112.7 |
| 80 | 128.7 |
Related: Free speed tools · How fast am I going right now? · GPS speedometer: live speed from your phone's satellites · GPS speedometer accuracy: how accurate is it? · Download speedometer app for Android or iPhone · GPS speedometer guide · Speed distance time calculator · Average speed calculator
Get Speedometer PRO on Google Play · Download on the App Store · Set it up before you move; never handle your phone while driving.
Sources
- GPS Accuracy (GPS.gov): gps.gov (accessed 26 October 2026)
- Location and sensors (Android Developers): developer.android.com (accessed 26 October 2026)
- CLLocation speed (Apple Developer documentation): developer.apple.com (accessed 26 October 2026)
FAQ
Does the online speedometer work on a laptop?
Only if the laptop has GPS, which most do not. Wi-Fi location is too coarse to measure speed, so you will see a dash or zero. A phone browser outdoors works much better.
Is my location sent anywhere?
No. The tool runs entirely in your browser and only stores your unit choice locally. Your position is never uploaded or logged.
Why does it show 0 while I'm moving?
Your device may not supply a speed value, or the signal is weak indoors or between tall buildings. Move near a window or outdoors and wait a few seconds for a better fix.
Can I use it while driving?
Only as a passenger, or with the phone set up and mounted before you move. Never tap or read the browser while driving; your car's speedometer remains the reference.
Does it work offline?
Once the page has loaded, satellite speed needs no data connection. If the page is closed you will need a connection to load it again.