Explore this interactive graphic to find out which are the biggest sites on the internet, as measured by the Nielsen company. This feature is part of SuperPower, a season of programmes exploring the power of the internet.

About this data

WHAT IS A TREEMAP? A treemap is a way of analysing large amounts of data in a small space In this example the top 100 websites have been depicted in proportion to the number of unique users they received in January 2010 A history of treemaps from the University of Maryland

The data used to generate the interactive treemap visualisation were collected by the Nielsen company and covers the UK, France, Germany, Italy, Spain, Switzerland, Brazil, US and Australia. The figures represent unique users for the month of January 2010.

The categories - such as retail, social networks, search/portal - were defined by the BBC. Because some websites have more than one use, they could fall within more than one category (e.g. Yahoo). However, the treemap only classifies them once.

The maps were produced using the Prefuse Flare software, developed by the University of California Berkeley.

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