That amounted to more than one-third of the working-age population and 400,000 more people than in 2009, Hill said.
"We can't say whether these are pricier one-off purchases, or multiple smaller purchases," he said.
"What we do know is that 45 per cent of online shoppers spent up to $100 online in the four weeks prior to being surveyed, and another 40 per cent spent up to $500 online.
Hill said what people are buying also appeared to be changing.
"We're not necessarily buying tangible items; over half of those who shopped online had at least one item delivered electronically. This may include items such as e-books, music, or e-tickets."
More than 70 per cent of New Zealanders aged 25-34 years and 68 per cent of people aged 35-44 years were opting for online shopping.
The Household Use of ICT Survey, which involved 15,000 private households and about 30,000 individuals aged 15+, also showed that four out of five Kiwi homes had access to the internet, 5 per cent more than in 2009.
"This 5 per cent increase since 2009 indicates that the rate of new connections is slowing, which is to be expected as it gets closer to 100 per cent of all households," Hill said.
Two-thirds of rural households had a broadband connection, an increase of 13 per cent since 2009. Wellington and Auckland had an 85 per cent connection rate.
Homes with children had one of the highest connection rates, at 88 per cent.
Hill said that for those without access to the internet at home, the main reason was a lack of interest, but cost was also an issue.
The number of households using more than one device to access the internet had almost doubled, from 21 per cent in 2009 to 40 per cent last year.
While the most popular combination was a desktop and a laptop in 2009, that had changed to a laptop and a mobile phone.
Laptops were the most popular means of accessing the internet in more than two-thirds of households.
One-third of households accessed the internet via a mobile phone, up 26 per cent since 2009.