In a "world-first", children worried about nude images and videos ending up online against their will, are able to report the material to help prevent it from being uploaded in the future.
Young people will be able to flag images and videos with the Internet Watch Foundation (IWF) charity via a new tool on the NSPCC’s Childline website before they have appeared online.
The Report Remove tool will allow under 18s to anonymously flag the material. IWF analysts will then review the content and create a unique digital fingerprint known as a hash, which will be shared with tech companies to help prevent it from being uploaded and shared.
The tool, described by the charity as the first of its kind in the world, can also be used to report an image or video that has already appeared online by sharing the URL. Analysts will assess the material and work to remove it if it breaks the law.
Young people must verify their age but do not need to share their real name with Childline or the IWF. Anyone who makes a report should receive feedback on the outcome in one working day.
Susie Hargreaves, IWF chief executive, said the tool will help give young people back control.
She said: "Once those images are out there, it can be an incredibly lonely place for victims, and it can seem hopeless. It can also be frightening, not knowing who may have access to these images.
"It will give young people the power, and the confidence, to reclaim these images and make sure they do not fall into the wrong hands online."
According to the IWF, reports of self-generated images more than doubled in the first three months of this year, compared with the same period last year.
A young person may have shared a sexual image with a partner that is subsequently shared without their consent, while others may have been groomed or blackmailed online.
Cormac Nolan, service head of Childline Online, said young people do not have to cope alone if they discover that a nude image of themselves has been shared online.
He said: "The impact of having a nude image shared on the internet cannot be underestimated and for many young people, it can leave them feeling extremely worried and unsure on what to do or who to turn to for support."
For support, children can contact a trained Childline counsellor on 0800 1111 or via 1-2-1 chat on www.childline.org.uk