GSMA today said its new online tool measures the ability of more than 130 countries to connect offline citizens to the mobile internet.

The GSMA Mobile Connectivity Index, which aggregates data from multiple sources, measures each country on the four enablers for driving mobile internet adoption – infrastructure, affordability, consumer readiness and content.

More than 3 billion people worldwide are accessing the internet via mobile. But more than 4 billion people are offline.

Approximately 3.2 billion people access the mobile internet at the end of 2015, representing about 44 percent of the population. About a third access the internet using 2G networks and two-thirds use mobile broadband on 3G and 4G networks.

Approximately 4.16 billion people, about 56 percent of the population, is not on the mobile internet. 2.5 billion or 34 percent of the population live within the footprint of a mobile broadband network but do not access services, while 1.6 billion or 22 percent live outside of a mobile broadband network footprint.

Mats Granryd, director general of the GSMA, said: “Mobile is the primary enabler of connectivity in developing world markets where the high cost of deploying fixed-line networks means that internet penetration is low.”

The Mobile Connectivity Index is accessible through a free web-based interface that allows users to explore in detail the performance of individual countries, compare countries against each other, said GSMA.