U.K. Prime Minister Keir Starmer announced Monday that children under 16 will be banned from using social media, citing concerns that the platforms are making young people "unhappy."
Some children's charities welcomed the sweeping change, which is likely to trigger a major fight with U.S. tech giants, but others warned it could make teenagers less safe online.
Starmer, likely to face a leadership challenge in the coming weeks, said social media sites were exposing children to content that is "dangerous" and "designed to be addictive."
The ban will "include platforms like Snapchat, TikTok, YouTube, Instagram, Facebook and X" but not messaging services such as WhatsApp, the government said.
Starmer said the upcoming ban was influenced by the experience of Australia, which in December became the first nation to ban people under 16 from social media.
He added during a press conference in Downing Street that he hoped to pass the regulation by late December and for the ban to come into force next Spring.
He suggested that YouTube Kids, Lego Play and Google Classroom would not be prohibited.
The government said in a statement it would also be considering overnight curfews and breaks in infinite scrolling for minors and would announce more details in July.
Australia's Prime Minister Anthony Albanese welcomed the move in a post on X, saying: "Social media giants operate across borders. By standing together, we can do more to hold them accountable and keep children safe online."
Canada and France are among other countries considering similar bans, while Indonesia began enforcing its ban for users under 16 in March.
Britain's ban could anger U.S. President Donald Trump after the U.S. embassy in London earlier this month came out against "broad social media bans."
Starmer's announcement follows a government-led consultation where British teenagers trialed social media bans and time limits on apps.
The National Society for the Prevention of Cruelty to Children called the ban "a win" for children and parents, but insisted that it must be followed up with "robust age checks on platforms" and "an effective enforcement regime."
Save The Children U.K.'s senior adviser, Jeffrey DeMarco, said his charity was concerned a ban "pushes children into less regulated spaces, where they are less likely to seek help when something goes wrong."
A spokesperson for YouTube responded with a warning that such a blanket ban would push children towards "less safe services."
The government also said it would block "harmful functions" on gaming services and live streaming platforms, allowing strangers to contact children.
"Is there a situation in the offline world where you would just let your child pair up with a stranger? An adult that you don't know about? No. So we're taking action on that," Starmer said, without giving details.
The U.K. government's consultation on the issue, which closed in late May, attracted about 116,000 contributions, making it the second-largest response ever received.
More than 83% of parents who responded said the risks posed by social media outweighed the benefits for children, with 91% backing a minimum age of 16.
The U.K. announcement comes a week after the government said tech giants must stop children in Britain from being able to send and receive nude images on their devices.
Britain's Interior Ministry said it was giving companies, including Apple and Google, three months to introduce safety features to block children from taking and accessing naked photos on phones and tablets.
If they failed to do so, the government would introduce legislation forcing them to activate the technology, it warned.
A law change would stop children from being able to access pornography, while also making it more difficult for child abusers to target children, it said.
According to an analysis by the Internet Watch Foundation charity, cited by the government, 91% of online child sexual abuse reports recorded in 2024 contained self-generated content from children themselves.
