Pornhub is the UK’s most visited website for adult content and it experienced a 47% decrease in traffic between 24 July, one day before the new rules came into place, and 8 August, according to Similarweb’s data.
Over the same time period, traffic to XVideos, another leading adult site, was also down 47% and OnlyFans saw traffic drop by over 10%.
The number of average daily visits to Pornhub fell from 3.2 million in July to 2 million in the first nine days of August.
However, the data also showed that some smaller and less well regulated pornography sites saw visits increase.
This comes after Virtual private network (VPN) apps became the most downloaded on Apple’s App Store in the UK in the days after the age verification rules were enforced.
VPNs can disguise your location online – allowing you to use the internet as though you are in another country.
The apps would also make it harder to collect data on how many people are visiting sites from specific locations.
Media regulator Ofcom estimates 14 million people watch online pornography.
It has set out a number of ways websites can verify the age of users including through credit card checks, photo ID matching and estimating age using a selfie.
Critics have suggested an unintended consequence of the changes could be to drive people to more extreme content in darker corners of the internet, such as the dark web.