Landmark online safety measures have failed to limit the proportion of children suffering harm from social media, the UK’s online regulator has admitted, in an assessment branded “staggering” by campaigners.

The proportion of children being fed unsafe content that often left them frightened, confused and upset, was almost unchanged, according to an Ofcom review of the first nine months of supposedly strict requirements on social media platforms such as TikTok and Instagram.

Under the Online Safety Act, the tech giants had to protect children from harmful content including pornography, serious violence, suicide material, racism, misogyny and bullying, with a series of specific duties introduced in summer 2025.

But Ofcom found that “at a total level there was no significant change in the proportion of children encountering harmful content over the first nine months after the children’s safety duties came into force in July 2025”.

It called the finding “concerning” and said there was no evidence indicating…