People are spending twice as much time online as they did 10 years ago because of the rise in smartphones and tablets.
New research from Ofcom shows that internet users aged 16 and over claim to spend more than 20 hours online each week - double the 10 hours stated just a decade ago.
The time spent online by 16-24-year-olds was found to have almost tripled, to 27 hours and 36 minutes.
One main reason for the increase was the continued growth of mobile devices, such as smartphones and tablets.
Since the iPad launched in 2010, tablet use has risen by more than 30%, with the 5% of those surveyed in 2010 saying they used a tablet rising to 39% this year.
Smartphone use among those who took part in the report has also more than doubled in five years - from 30% in 2010 to 66% now.
Gadget expert and founder of technology website pocket-lint.com, Stuart Miles, said that sites like Facebook and Twitter were also playing a role in driving more users online for longer.