What this is

Pocket Speedometer reads your phone's GPS and shows how fast you're going. That's all it does. Open the page, let the browser see your location once when it asks, and your dial starts reacting the moment you start moving.

You won't find a sign-up form anywhere. There is no upgrade nag. The page is not going to ambush you with an ad two miles into a drive.

I bothered building this because the free ones I kept finding online were not actually free. After a few days they paywall the bigger digits. Or they wrap a video ad around the readout. Sometimes, somehow, both. A speedometer is a tiny idea. It shouldn't be doing all that.

How to use it

Pull the page up on your phone. The first time, the browser will ask whether the site can use your location. Say yes once and the question goes away forever. Up near the top corner you can spot a small dot. When the GPS gets a fix, that dot turns green and the dial starts moving with you.

The unit label, sitting right under the speed reading, is a button. Tap it to cycle through km/h, mph, knots, and m/s. Whichever one you stop on will be the one that loads next time.

Two switches sit above the dial as well. One of them swaps you to the analog face. The other gets you a big plain digital number. The digital is what you want if your phone is clipped to a handlebar or shoved into a dash mount, where a tenth-of-a-second glance is all you have.

Down at the bottom there are three small numbers. The first is the highest speed you have hit since you opened the page. Average for the session sits in the middle. On the right end is the GPS accuracy itself, in metres. Smaller number means a tighter fix.

You can install it as if it were a real app, by the way. Open the page in Safari on iPhone, hit the share button, and pick Add to Home Screen. On Android, Chrome usually pops up an install prompt by itself. If yours does not, the option is buried in the three-dot menu. Once it is on your home screen the icon takes you straight to the dial. No browser chrome above it. No tab you can lose somewhere halfway down a long drive.

Questions people ask

Is it actually free?

Yes, really. Nothing's locked, there is no trial waiting to flip into a subscription, and you skip the account step entirely. The page costs about as much as a coffee per year to run. Charging for a number on a screen was never going to add up.

Does it work without internet?

The very first time, you need a connection so the browser can fetch the page. After that, the page itself runs without one. And GPS (the actual satellite thing) never needed mobile data in the first place. Your phone is talking to satellites way up overhead. That's why a hike somewhere with zero cell signal still tells you exactly where you are. Add the site to your home screen and it'll keep going in airplane mode, as long as Location Services itself is on.

It says "GPS off" and nothing moves. What now?

Easiest one to check first: did you actually give the browser permission to see your location? Look for the little location icon up in the address bar and click it to allow. That fixes it most of the time.

If permission is already on, you are probably indoors. GPS is weirdly bad at getting through concrete, which is why a basement or a parking garage will kill the fix entirely. Walk over to a window or step outside for a minute.

There is a third reason that almost never comes up in normal use, but it's worth knowing about. The page has to be served over https. Browsers refuse to hand over location data on a plain http page on purpose. The live site is https, so this one only bites when you're poking at a local copy.

How accurate is the reading?

Out under open sky, your phone is usually reporting position accuracy somewhere between three and ten metres. The speed reading comes within a kilometre or two an hour of the actual truth. Sometimes closer than that.

Here's something nobody really tells you. Car speedometers in production cars are legally not allowed to read low. Which means pretty much every one of them reads a little high on purpose. The GPS reading is the honest one. That is the gap that's behind all those "my dashboard said 65 but the speed camera clocked 60" stories you hear.

Can I use this in a car? On a bike? Running?

Yep, any of those. The dial scales itself to whatever you happen to be doing. Walking it'll hover somewhere around 10. In a car it stretches itself out to wherever you're driving to. Readings come in about once a second, which is plenty unless you're trying to time apexes on a track day. Knots are in there for anyone who is actually on a boat.

Will it drain my battery?

GPS uses a little power, sure. The bigger drain, weirdly, is the screen. The page asks your phone not to dim while you have the dial up, and a screen lit at full brightness is what really eats your battery. For a quick run to the shop or a half-hour ride, you will not notice. For a long drive, just plug into a charger and forget about it.

Are you tracking me?

Nope. There is no analytics on the page, no third-party trackers, and the host's basic access log is the only server-side record anywhere. The location your browser reads stays right there in your browser. It moves the dial until you close the tab, and then it's gone. Nothing leaves your device, because I never built anywhere for it to land.

Does it work on a laptop or desktop?

Not really, no. Laptops almost never come with a real GPS chip, so the browser ends up guessing where you are by looking at nearby Wi-Fi networks. That sort of works for figuring out which city you are in. It is useless for how fast you happen to be going. Rather than show a number that's basically invented, the desktop view replaces the dial with a QR code. Point your phone camera at the code and you'll land on the same site, on a device that actually has GPS hardware in it.

Why is the speed jumping around?

The reading gets noisier whenever the fix is weak. Heavy tree cover is a common cause. So is walking down a street with tall buildings on both sides. For a minute or two after you come out of a tunnel, expect some wobble too. Low speeds make this worse, because tiny position errors get amplified into much bigger velocity errors. The app already smooths the reading a little so the dial doesn't twitch with every fix, but you'll still catch the occasional wobble. Come to a full stop, wait a couple of seconds, and it'll settle back to zero.

Is there a native iPhone app?

One's on the way. The web version went out first because it was the version I could put in front of people without an app store sitting in the middle of things. The iOS app is being built right now. It will appear in the store as soon as Apple is done with the review.

Why did you build this?

I wanted a clean GPS speedometer on my phone. None of the ones I tried felt like anything other than a hostage situation. So this is what I ended up doing instead.