And people, on average, spend two hours online on their smartphones.
Ofcom said that a third of internet users regard the smartphone as the best device for going online, compared to 30 percent who use notebooks.
And 66 percent of adults in the UK have a smartphone, up from 39 percent in 2012. For people aged between 55 and 64, smartphone ownership has doubled since 2012, from 19 percent to 50 percent.
Ofcom said that smartphone users with 4G shop online more than those without 4G, with 57 percent watching more TV and video clips, and instant messaging using WhatsApp and the like.
Four in 10 British people can choose 4G from EE, O2, Three and Vodafone. By 2019, Ofcom estimates that 98 percent of premises will have an indoor 4G signal.
People are also using smartphones to take photos with 60 percent using their phone rather than any other device, including digital cameras.
Ofcom said that nearly half of young people between 18 to 24 check their smartphones for messages within five minutes of waking up.