Half of schoolchildren admit they have seen sexual, violent and other adult material on social media sites, apps and games.
And 78 per cent of children say they had joined social media sites before reaching the minimum age of 13, as is a requirement on most sites.
The findings are revealed in the new Net Aware guide, produced by the charity NSPCC to give parents information about the current most popular sites for young children and warn of the content they can readily access online. Child campaigners say they hope the findings will encourage more families to regularly make time to talk to their children about socialising safely online.
Peter Wanless, NSPCC chief executive, said: “As a parent it can be difficult to keep up with the many different websites, apps and games our tech-savvy children know so well.
“It’s vital parents actively participate in their children’s digital life to help them stay safe online.”
Almost 2,000 youngsters aged between 11 and 18 across the UK were questioned for the research along with 500 parents of children aged between eight and 12. Six in ten of the children said they believed social media platforms need to do more to keep children like them safe from content and from abuse from other users.
The top five sites where young people reported seeing inappropriate content were Sickipedia (100 per cent of children surveyed), Chatroulette (92 per cent) Omegle (89 per cent) Ask.fm (88 per cent) and Yik Yak (74 per cent).
The NSPCC has called for minimum standards to be put in place to protect children whey they are online and say a new regulator should be put in place if industry can not regulate itself. It also wants to see all social networking accounts for under-18s to alert children when they interact with an adult online and set profiles as private by default at sign-up, ensuring location details are turned off to prevent adults using the sites to groom youngsters.
The charity also wants sites with violent or sexual material to provide age appropriate safety reminders to children when they communicate with new users and before they are able to send images,
The Information Commissioner’s Office is currently reviewing websites apps used by children now, as part of an international project to consider privacy concerns around the type of personal information services collect.