The logo for YouTube Inc. is displayed on a smartphone in an arranged photograph taken in the Brooklyn borough of New York, U.S., on Sunday, May 10, 2020. The video arm of Alphabet Inc.'s Google is offering new tools and audience statistics specifically for advertising on TV - screen space where YouTube has trailed cable channel. Photographer: Gabby Jones/Bloomberg 
Adults spend an average of four and a half hours online a day, Ofcom said in the Online Nation 2025 report, up 10 minutes on last year.
YouTube was Alphabet's most popular service in Britain, used by 94% of adult internet users in May 2025, according to Ofcom, beating Google Search, which was used by 82% of online adults.
The combination of Facebook and Messenger remained the most widely used Meta-owned service, used by 93% of online adults, the report said, while WhatsApp was used by 90%.
The growing popularity of YouTube shows how the media landscape is rapidly changing in Britain, with traditional linear broadcasters losing audience share to social media sites dominated by Alphabet and Meta.
Pay-TV group Sky, owned by Comcast CMCSA.O, last month said it was in talks to buy ITV ITV.L, Britain's biggest free-to-air commercial broadcaster.
Former ITV chairman Peter Bazalgette said when the talks were announced that regulators needed to redefine the ad market to take account of competing digital services, such as YouTube.
Meta and Google captured about 60% of UK ad spend in 2024, while Google's YouTube was the second most watched service, behind only the BBC, Ofcom said in July.
(Reporting by Paul SandleEditing by Alexandra Hudson)