Cable.co.uk ran 1.3 billion tests in 220 countries for a year to complete the survey.
It found Jersey was the quickest after it became the first jurisdiction in the world to make pure fibre available to everyone with broadband.
The island topped the list with a speed of 264.52Mbps, Liechtenstein came second and Macau third.
According to the study, many of the countries and jurisdictions at the top of the list are small because that's advantageous when rolling out stronger broadband.
Guernsey came 52nd on the list.
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