If you are using Windows, Chrome's built-in browser, and measure on a connection that has a 150 Mbit/s or more in capacity there is a risk that the result will not be reliable.

This is not just a problem with Bredbandskollen. Other Web based measurement tools also have problems with this combination.

We recommend that you double-check your measurement results in another browser or another measurement tool, e.g. TPTEST that is available for download on our website. Also, make sure you upgrade your operating system and Web browser to their latest versions as this is likely to solve the problem.

A user also gets information on this after completing a measurement. 

Bredbandskollen can measure connections with speeds up to 1 Gbit/s.