Girls and young women are seeing more unwanted sexual images and suffering more cyberstalking online, but still don’t want to take a break from social media because of a fear of missing out, a survey for Girlguiding has found.

“Fomo” is keeping more than half of 11- to 21-year-olds on apps such as TikTok, Snapchat and WhatsApp despite nearly one in five saying they have been being stalked online and more than a third saying they are seeing sexual images they didn’t wish to see, the survey of more than 2,000 girls and young women found.

The incidence of both online harms is up year on year, according to the findings, which also showed half of girls and young women aged between seven and 21 feel anxious about their futures, and only a quarter feel very confident in their life.

Despite the reluctance to take a break, only 37% of girls and young women aged 11 to 21 are reporting that they feel they have strong connections online, and this number has been falling over the last four years.

The findings came as thousands of parents and schools signed up to a pact for a “smartphone-free childhood” amid official figures showing that only one in 10 UK 12-year-olds does not have their own smartphone.

“In my daily life, I see how the constant pressure to meet unrealistic beauty standards and the normalisation of sexism leaves girls feeling vulnerable and unsupported,” said Jiya, 17, a Girlguiding advocate. “Being online all the time amplifies this. While we’re ‘more connected’, we’re also more exposed to judgment and comparison – through body shaming, sexist jokes, online harassment and objectification. This fuels loneliness and erodes our confidence, which only makes it harder to feel positive about the future.”

Eight-five per cent of those who responded to the survey said they experienced sexism in their daily lives, just over half from sexist comments in real life rising to almost three-quarters online.

Girlguiding said: “This appears to be having a knock-on effect on girls’ sense of safety, with almost half of girls (47%) aged 11 to 21 revealing sexism and misogyny makes them feel less safe, more than double the number of girls who reported feeling this way 10 years ago.”

Angela Salt, the chief executive of Girlguiding, said it was “devastating to see girls feel less confident about themselves and their futures”.

“Sexism continues to be pervasive, leaving many girls feeling vulnerable and unsafe,” she said. “We’re glad to see the government is taking rising levels of misogyny seriously. Now it’s been acknowledged as a problem, we are determined to make sure the voices of girls are heard as part of the solution.”

The Home Office has said that it intends to start treating extreme misogyny as a form of extremism and announced a rapid review of how best to crack down on this and other harmful ideologies in August. Girlguiding is calling for new relationships, sex and health education resources in schools, “to tackle sexism and misogyny and encourage better, healthier relationships”.

On the upside, 44% of girls and women between seven and 21 said they feel hopeful and a similar number are curious about the future.