A speedometer, not a funnel.

Search for an online speedometer and you find two kinds of site. The first shows you a dial and nothing else — no accuracy figure, no trip record, no way to get your own data back out. The second shows you a dial, lists trip logging, HUD mode and speed history as features, and then makes every one of them a reason to download an app.

None of those features need an app. A browser can read GPS, keep a screen awake, store a trip and export a GPX file. So this site does all of it, on the page you are already looking at, for free.

What it does differently

• It shows its working. The accuracy radius, whether the speed came from your device’s Doppler sensor or was derived from position changes, and how many fixes were filtered out — all visible while you drive. A number with no error bar is a number you cannot judge.
• It filters aggressively. Fixes worse than ±30 m are discarded, readings implying over 400 km/h are treated as GPS jumps, and distance only accumulates while you are genuinely moving. Without that last rule a parked phone records kilometres it never travelled.
• It separates moving time from elapsed time. Average speed and average moving speed are different numbers and both are shown, because a ride with a café stop is not a slow ride.
• It keeps the screen on. The Wake Lock API, one line of code, and the difference between a usable in-car display and a black rectangle.

What it deliberately does not do

• No accounts, because there is no server to hold one.
• Analytics you can switch off, from the privacy page, whenever you like. Where prior consent is required you are asked before anything loads at all. Neither the analytics nor the advertising that pays for the site ever sees your location.
• No app-store upsell. There is no app.
• No speed-camera or enforcement data. Obey your car’s speedometer for legal purposes — see why it reads higher than GPS.

Requirements

Any browser with the Geolocation API and a device with a GPS receiver — in practice, any phone made in the last decade. The page must be served over HTTPS, which browsers require before granting location access. Desktop computers without GPS hardware will fall back to a network-derived position, which is far too coarse to produce a meaningful speed.

Accuracy, honestly

In good conditions this reads within about 1 km/h of your true speed. In tunnels, dense cities and under heavy tree cover it will be worse, and it will tell you so rather than showing a confident wrong number. Read the full explanation if you want the detail.

Who made this

I wanted to know how fast a vehicle I was travelling in was actually going, and none of the pages I found would tell me how much to trust the number they were showing. So I built one that does.

It is written and maintained by one person — Abhishek — and it is not a company, a startup, or a product with a roadmap. That is also why the accuracy figures here are stated plainly rather than buried: their absence everywhere else is the reason this site exists.