The figure was released by communications industry watchdog, Ofcom.
According to their report, a third of all online access in the UK is via smartphones, up from 23 percent in last year.
Head of the research team Jane Rumber says the result took them by surprise.
"One of the most striking findings in our report this year is that smartphones are now the UK's most important device for getting online, overtaking laptops for the first time."
The rise in mobile web surfing has been partly driven by the expansion of high-speed 4G data networks and the growing popularity of streaming video.
On average, adult mobile users spent nearly two hours online each day using a smartphone, compared to just over an hour on laptops and PCs.
One particular user from London says it's hard to keep away from a smartphone once you're in the habit of using it.
"I'm one of those people that before I had one was really anti (against having a smartphone). I think it takes over people's lives and whatever. But I have slightly become one of those people, but I try and refrain (from letting it take over my life)."
The research also found more people are using smartphones to take and post pictures.
But for some taking selfies is not the only use for the function.
"I tend to take pictures of things, rather than put myself in everything. That's just an old person's way of using a smartphone"
"I'm not massively into selfies. I sometimes do it after I have a haircut, just to see what it looks like."
Other results from the report show traditional forms of communication still prevail.
Adults in the UK are still posting six letters, cards or parcels in an average month, only a slight dip from the numbers two years ago.
For CRI, this is Fu Yu.
