Make sure you are in GPS mode in location settings.
Make sure you gave permissions to this website and the browser.
Zpeed - Online Speedometer in your pocket
Zpeed helps you find your real-time speed in km/h. No installation needed. Use it right away! Zpeed is a progressive web app which you can use offline in latest browsers like Google Chrome.
If you find Zpeed useful, please tweet about this.
Some browsers and devices have support issues with geoLocation API. If you are not getting correct location, make sure you are in GPS mode in location settings and you gave location permission to both the Browser and Webpage. Or, try with another browser. :)