According to the study commissioned by Google South Africa, the country had 8.5 million internet users in 2011, compared to 6.8 million people in 2010.

"This growth brings internet penetration in South Africa to approximately 17 percent," said the report.

"Despite rapid growth, however, it lags significantly behind the biggest internet user bases in Africa".

Oil-rich Nigeria, which is also Africa's most populous nation, has the highest internet penetration at 29 percent, followed by Egypt, Morocco and Kenya.

Growth in South Africa, the continent's largest economy was attributed to the propagation of smartphones to access the internet, which took off in 2008.

"It should also be borne in mind that access and cost remains the biggest obstable to internet connectivity, particularly in less developed areas," said Luke Mckend, Google SA country manager.

This year's arrival of an undersea fibre-optic cable, which connects large parts of Africa with the world was expected to improve broadband connectivity across the continent.

The cable has landing points in 10 other countries along Africa's western coast and its arrival promises an Internet boost for Africa, where only 9.6 percent of people are web users, compared to 65 percent of Europeans.