VaneOnline GPS Speedometer
Open this page on your phone, tap Start, and allow location access. It reads your speed from the phone's satellite positioning, in km/h, mph or knots.
Tap Start and allow location access.
- Top
- --
- Average
- --
- Distance
- --
- Moving
- 0:00
- Accuracy
- --
- Scale
- --
Your position never leaves your device: the speed is worked out in your browser, and nothing about where you are is sent anywhere.
How to use it
- Open vanedash.com/speedometer on your phone, not a laptop.
- Tap Start and allow location access when the browser asks.
- Give it a few seconds outdoors to get a satellite fix. The accuracy figure should drop under about 20 m.
- Tap Keep screen on so the phone does not lock. If the screen locks or you switch apps, the browser stops receiving positions until you come back.
The head-up display shows the speed mirrored, very large, on black. At night, lay the phone flat on the dashboard, below the windscreen, with its top edge towards you, and the reflection in the glass reads the right way round. Set it up before you drive, or hand the phone to a passenger.
Why it does not work on a laptop
Speed needs a satellite (GNSS) receiver. Almost every phone has one. Most laptops, desktops and Wi-Fi-only tablets do not: they work out their location from nearby Wi-Fi networks or the IP address, which is accurate to tens or hundreds of metres and carries no speed at all. When the page sees an accuracy that coarse, it says so instead of showing a made-up number.
Where the number comes from
The browser's location interface reports a speed value, in metres per second, when the
device knows it. On phones that figure usually comes from the satellite receiver itself, which measures
speed from the Doppler shift of the satellite signals rather than from position changes. Studies of
phones put that at about 0.1 to 0.4 m/s, roughly 1 km/h, in open sky. Some browsers leave it empty. In that case the
page measures how far you moved over at least three seconds and divides by the time, which is
noisier, especially at walking pace. The small label under the number says which one you are
seeing. How GPS measures speed explains both.
Common questions
Is this speed more accurate than my car's speedometer?
Usually, yes, at a steady speed in open sky. Car speedometers are allowed to read high and most do by a few percent, while phone GPS speed is typically within about 1 km/h. Neither is a legal reference: drive by the posted limit and your vehicle's own speedometer.
Why does it show dashes?
Dashes mean there is no trustworthy speed: no satellite fix yet, a location that came from Wi-Fi rather than satellites, or no new position for several seconds, as in a tunnel.
Does the online speedometer need mobile data?
Loading the page needs a connection. After that, satellite positioning works without data, although a phone with no recent data can take longer to get its first fix.
Why does it not work on my laptop?
Most laptops and desktops have no satellite receiver. They locate themselves from Wi-Fi networks, which is accurate to tens or hundreds of metres and reports no speed. Open the page on a phone instead.
Does it work on a plane?
Often, from a window seat with the phone in airplane mode. The satellite signal comes in through the window; an aisle seat usually gets nothing.