Australian children who join Facebook will automatically have tighter privacy settings under a global shift by the social media giant to protect young people.
The change will kick in on Tuesday for Australian children under the age of 16, and teenagers already on the app will be prompted to limit what other people see on their profiles.
That includes their friends list, people and pages they follow, and what posts they're tagged in.
The shift is part of a suite of measures touted by Facebook's parent company Meta designed to make the social networking site, along with Instagram, safer for teenagers.
Default privacy settings for children have already been rolled out on Instagram, which is also owned by Meta.
Meta vice president and global safety head Antigone Davis said in a blog post on Tuesday the company was testing further ways to stop teenagers from messaging "suspicious" adults they didn't know.
Adults can be blacklisted as suspicious by Facebook and Instagram if a young person has recently blocked or reported them.
Under testing, those adults won't show up in teenagers' suggestions for "people you may know".
Instagram is also trialling removing the message button on children's profiles when suspicious adults click on them.
In addition, Meta is working with the US-headquartered National Center for Missing and Exploited Children to create a global platform for teenagers who are worried their intimate images might be shared online without consent.
The platform will help Meta prevent those images from being posted online, and other technology companies will also be able to use it, according to Ms Davis.
"The non-consensual sharing of intimate images can be extremely traumatic and we want to do all we can to discourage teens from sharing these images on our apps in the first place," she said.
The social media giant is planning a campaign to stop people sharing exploitative child content online.
Research by Meta suggests more than three-quarters of people who post exploitative child content on social media don't have malicious intent - instead, they're posting out of outrage, poor humour, or disgust.
The new default privacy settings will apply to teenagers under the age of 18 in select countries.