GPS Speedometer Online
A free GPS speedometer online that shows how fast you are moving, using your phone's own GPS, in km/h, mph or knots. It cannot measure speed on a laptop or indoors, where there is no GPS fix; it says so instead of guessing.
Tap Start to read your speed from GPS.
How This GPS Speedometer Online Works
This GPS speedometer online reads your phone's satellite position through the browser's Geolocation API and shows your speed over the ground, updated with each new fix. When the phone reports its own speed, the page shows that number directly. When it does not, the page works speed out from the distance between two accurate fixes and the time between them. Nothing is installed and your position never leaves the phone. Updated 2026-10-18.
Under the big number you see how the speed was measured (GPS speed or position change) and how accurate the current fix is, as the radius the browser reports, in metres. Below that are the trip figures: max speed, average speed while moving, distance and moving time. Tap Reset trip to start them again.
When you stand still, a GPS position wanders by a few metres. So the page shows 0 below 0.5 m/s (1.8 km/h, about 1.1 mph) and does not add that drift to the trip distance. If no new fix arrives for 10 seconds, the number turns grey and the line under it says how old it is.
How Accurate Is a Phone GPS Speedometer?
Under open sky, the U.S. government's GPS.gov says GPS-enabled smartphones are typically accurate to within a 4.9 m (16 ft) radius. Speed is usually better than position, because most phones measure it from the Doppler shift of the satellite signals rather than from position jumps. In practice that means a steady drive on an open road reads close to the true speed. The reading gets worse in these places:
- Indoors, tunnels and car parks: no satellites, so no speed at all. The page shows "--" rather than a number.
- Between tall buildings: signals bounce off walls and the fix can jump. Watch the accuracy line; anything marked poor is not used for max speed or distance.
- Hard braking or quick acceleration: fixes arrive at intervals, so the number trails a fast change by a moment.
- Laptops and most tablets: they locate you by Wi-Fi, to tens or hundreds of metres, which is far too coarse for speed. Open the page on your phone.
Your car's speedometer is a different instrument. Under UN ECE Regulation 39, which covers cars sold in Europe and many other markets, a speedometer must never show less than the true speed, so most read a little high, and a GPS speed slightly below the dashboard figure is normal. For anything that matters legally, the vehicle's own speedometer is the one that counts.
km/h, mph and Knots
All three units come from the same reading in metres per second. The conversions are exact: one mile per hour is 1.609344 km/h, because the international mile is defined as 1,609.344 m, and one knot is 1.852 km/h, because the international nautical mile is defined as 1,852 m. The page picks mph if your phone is set to US or UK English and km/h otherwise; tap a unit to change it, and the choice is remembered.
| km/h | mph | knots | m/s |
|---|---|---|---|
| 10 | 6.2 | 5.4 | 2.8 |
| 50 | 31.1 | 27.0 | 13.9 |
| 80 | 49.7 | 43.2 | 22.2 |
| 100 | 62.1 | 54.0 | 27.8 |
| 120 | 74.6 | 64.8 | 33.3 |
Using It in a Car, on a Bike or on a Boat
Put the phone where it can see the sky: a dashboard or windscreen mount is better than a cup holder or a pocket. Tap Keep screen on so the phone does not lock mid-trip; a browser may stop sending positions while the screen is off or the page is in the background. Mirror for HUD flips the number so you can lay the phone under the windscreen at night and read its reflection. Knots are there for boats, where a GPS speed over ground is exactly what a chart plotter shows.
If you are driving, set it up before you leave and do not handle the phone on the move. A passenger can check the speed, start a trip or reset it.
Frequently Asked Questions
Is this GPS speedometer online free, and do I need an app?
It is free and nothing is installed. It works like a speedometer app on Android and iPhone but runs in your browser. To open it like an app, use your browser menu and choose Add to Home screen.
Why does it show -- instead of a speed?
There is no usable GPS fix yet. Indoors, in a tunnel or on a laptop the browser only gets a rough Wi-Fi location, which cannot measure speed, so the page shows -- rather than invent a number. Go outside with open sky and give the phone a few moments to find satellites.
I blocked location. How do I turn it back on?
The page needs location to measure speed. On Android Chrome, tap the icon left of the address, open Permissions and allow Location, then reload. On iPhone, open Settings, Privacy and Security, Location Services, Safari Websites, choose While Using the App, then reload the page.
Why is the GPS speed lower than my car speedometer?
Under UN ECE Regulation 39 a car speedometer must never show less than the true speed, so most read a little high and a GPS speed slightly below the dashboard figure is normal. On an open road, a phone that reports its own Doppler speed is usually the closer of the two, but the vehicle speedometer is the one that counts for the law.
Does it work offline or in airplane mode?
GPS itself needs no internet, so once the page has loaded the speed keeps working without mobile data. Some phones turn GPS off in airplane mode; if the speed stops, turn Location back on.
Will it keep working with the screen off?
Usually not. Browsers stop sending positions to a page that is hidden or behind a locked screen. Tap Keep screen on before you set off; time with no fixes is not counted as moving time.
Is my location stored or sent anywhere?
No. The positions are processed only in your browser to work out speed and distance. Nothing is uploaded. Only your choice of unit is saved, on this phone.