Akamai Technologies' third quarter "State of the internet" report also showed China remained the biggest source of computer attacks, and that Brazil and China appear to have the biggest surge in web use.
The global average connection speed decreased by some 7% between the second and third quarters of 2012 to 2.8Mbps.
But that appeared to be a temporary decline, since average connection speeds were up 11% year over year.
South Korea continued to have the highest average connection speed at 14.7Mbps, followed by Japan (10.7 Mbps) and Hong Kong (8.9 Mbps).
Globally, adoption of "high" broadband (speeds above 10 Mbps) grew 8.8% in the third quarter and overall global broadband adoption grew 4.8%, the report said.
For the second quarter in a row, Brazil experienced the greatest year-over-year growth of 39% within the group of top 10 countries. China showed the largest quarter-over-quarter increase of 5.7%.
In analysing web attacks from 180 countries or regions, Akamai said China remained the single largest source, with 33% of all attacks originating within its borders.
The US accounted for 13%, followed by Russia at 4.7%.
For the mobile internet, Akamai said Apple's Mobile Safari accounted for 60.1% of data requests on all networks, with Google's Android browsers responsible for 23.1%.