New online safety measures have so far not “significantly” changed the amount of children suffering harm from social media, the online regular has said.
Duties under The Online Safety Act, a law aimed at protecting children and adults online from harmful content, came into force in July 2025.
Tech giants had to protect children from harmful content including pornography, serious violence, suicide material, racism, misogyny and bullying.
Most children in the UK say they have encountered at least one piece of harmful content online in a four-week period, according to an Ofcom review on content harmful to children online has found.
It adds: “According to our evidence, 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.”
This finding is “concerning and shows that further progress is needed to protect children online”, Ofcom said.
Children have come across graphic, extremely violent content on regulated services, include gore content and graphic footage of real life violence.
Some children said they had been affected after seeing footage of the death of conservative activist Charlie Kirk, who was shot in September 2025.
Violent content left children feeling worried, upset, frightened or angry around half of teenagers who were exposed to weapon-related content admitted it made them feel less safe in their school or neighbourhood.
The report found that 14% of 11 to 17-year-olds said they were exposed to suicide or self-harm content in the previous four weeks while 23% said they had seen eating disorder content.
Among this group, 49% of the children also said they had been exposed to hate content in the previous four weeks.
Ofcom’s review included a tracking survey of UK children aged 8 to 17 to find out about their exposure to harmful content on user-to-user services, along with their response to it and the use of safety tools.
Children also took part in an online insights panel and various other pieces of research were carried out, including looking into their encounters with illegal or inappropriate content and search services.
The information is being passed on to Culture Secretary Lisa Nandy.
The report adds: “Exposure to harmful content can have serious impacts on children’s mental and physical wellbeing.
“Children continue to report that encountering harmful content negatively impacts their wellbeing.
“There is no new evidence indicating a change to the severity of harm experienced by children as result of encountering harmful content.”
An Ofcom spokesman: “Our report on content harmful to children clearly shows that tech firms need to go much further and faster to protect children online.
“This is an industry that’s been unregulated and unaccountable for more than 20 years.
“And so while significant progress is being made, including the introduction of widespread age checks, stronger protections against grooming, and tougher safeguards against child sexual exploitation and abuse, we’re under no illusion that there is much for the industry still to do.
“We’ve shown that tech firms that don’t comply with their duties can expect enforcement action.”
Linda Jardine, director of children and family services at Children First, described the report as a “stark picture of the overwhelming levels of danger that children face on screens”.
She said: “Young people, who we supported to contribute to the report, said they regularly see content about pornography, suicide and self-harm and that content in relation to bullying, hate, abuse, violence, harmful substances and encouraging dangerous stunts and challenges is ‘everywhere’.
“Ensuring that the Online Safety Act accurately reflects the types and severity of content that children see online is crucial, but unless the level of exposure is reduced, children will continue to experience significant harm to their physical and emotional health, wellbeing, relationships and development.”