Porn users could have their faces scanned to prove their age, with extra checks for young-looking adults, draft guidance from Ofcom suggests.
The watchdog has set out a number of ways explicit sites could prevent children from viewing pornography.
The average age children first view pornography is 13, a survey suggests.
Explicit website Pornhub said regulations requiring the collection of “highly sensitive personal information” could jeopardise user safety.
Privacy campaigners have also criticised the proposals warning of “catastrophic” consequences if data from age checks is leaked.
A large chunk of the UK population watch online pornography – nearly 14 million people, according to a recent report by Ofcom.
But the ease of access to online pornography has also raised concerns that children are viewing explicit websites – with one in ten children seeing it by age nine, according to a survey by the Children’s Commissioner.
The Online Safety Act, which recently became law, requires social media platforms and search engines to protect children from harmful content online.
It will be enforced by Ofcom, who can issue large fines if firms fail to comply.
Ofcom has now outlined how it expects firms to become “highly effective” at complying with the new regulations, which come into force sometime in 2025.