New figures show a massive increase in mobile phone data downloads, with Australians downloading 20,000 terabytes of data in the three months to June this year.

That is a 43 per cent jump from the previous period of October to December 2012, the latest figures from the Australian Bureau of Statistics show.

"Download volumes for mobile handsets have really seen explosive growth," the ABS's Lesley Martin said.

"And while it's true that the number of mobile handset internet subscribers has also increased, that's been much smaller growth."

In the three months to June, Australia's total download volume hit 657,000 terabytes, up 18 per cent.

Australia had more than 12 million internet subscribers - not including mobile handsets - at the end of June.

Social media, music streaming boost data usage

Foad Fadaghi, a senior analyst at research firm Telsyte, said the increase was fuelled by the introduction of 4G mobile networks, which offer faster speeds and encourage more downloads than 3G networks.

"People have started using mobile apps for many of the things they used to do on computers," he said.

The use of social media apps such as Facebook, Twitter and Instagram has "exploded" in the past year, he said.

Music streaming services such as Pandora and Spotify were also boosting the amount of data people use.

The results come as analyst firm IDC released figures showing mobile phone shipments are down 20 per cent on 2012.

The drop has been driven mainly by a 45 per cent drop in shipments of feature phones - old-style mobile phones - but IDC said there has also been a "slight decline" in smartphone shipments.

ABC/AAP