How Speed Tracker Works

This page describes the current browser implementation, not an independent laboratory test. Browser and operating-system updates can change the location values a device provides.

1. Where the location values come from

After the visitor grants permission, the page calls the browser Geolocation API. The browser asks the operating system for location updates, which may combine satellite navigation with other available signals. This website does not directly control the phone's satellite receiver and cannot promise a particular satellite count or accuracy.

The page requests high-accuracy location where the browser supports that option. Actual accuracy depends on the device, environment, permissions, operating system and available signals. Indoors, between tall buildings, in vehicles with signal-blocking glass, or during poor reception, updates may be delayed or noisy.

2. Speed display

The tool reads the speed value supplied in the browser's location coordinates when that value is available, converts metres per second to kilometres per hour, and displays zero when the value is missing or below its small display threshold. The browser may return a null speed value; a displayed zero therefore does not prove that the device has measured a perfectly stationary state.

The unit switch converts displayed speed to miles per hour when selected. The dial is a visual representation of the displayed estimate; it does not add a separate measurement source or improve accuracy.

3. Trip-distance estimate

The page calculates the straight-line distance between consecutive latitude/longitude updates using a spherical-distance formula. It adds a segment only when the segment is greater than 2 metres and less than 500 metres. These thresholds reduce some tiny movements and unusually large jumps, but they cannot eliminate drift or reconstruct every road bend between updates.

This means the result is an estimate from sampled positions, not a surveyed route distance. A route may be undercounted if updates are missed or turns are skipped, and overcounted if location drift makes a stationary device appear to move. Resetting the trip counters starts a new on-screen session.

4. Direction and nearby place name

Direction is calculated from consecutive positions when the compass option is not active. That makes it a direction-of-travel estimate, not necessarily the direction the phone is facing. If device orientation is available and enabled, the browser may provide a compass-related reading, but hardware support and calibration vary.

To display a nearby place name, the page requests a reverse-geocoding result from OpenStreetMap Nominatim. That request sends the coordinates needed for the lookup to the service. The service may return a road, neighbourhood, town or postcode when available; the returned label is not a guarantee of an exact postal address.

5. Saving statistics

The “Save Current Stats” action stores the displayed top speed, trip distance and save timestamp in the browser's local storage. It does not create a cloud account or upload these saved statistics to a Speed Tracker application server. Local storage may remain after the tab closes and can be cleared using browser site-data settings.

6. Practical checks for a more useful session

1. Use a supported browser on HTTPS and grant location permission only if you want live readings.
2. Start outdoors with a relatively open view of the sky, then wait for updates to settle.
3. Keep the phone secured and do not interact with it while driving or cycling.
4. Compare repeated readings rather than relying on a single jump or peak.
5. Note that this tool does not certify a vehicle instrument, route distance or safety-critical measurement.

7. What this page does not claim

We do not claim laboratory validation, a guaranteed accuracy percentage, universal compatibility, a complete route recording service, or aviation/automotive certification. The tool is offered as a general-purpose estimate. If a reading matters for a legal, medical, emergency or safety decision, use an appropriate certified device or qualified professional.

Related information

How trip distance is estimated · What the tool measures · Privacy policy · Terms of use