Governments have increasingly sought to limit access to online content over concerns about addiction, misinformation, and harm to minors. Yet regulating activity online can be difficult. Users may circumvent restrictions by using technologies such as virtual private networks (VPNs) and by switching to websites that do not follow the rules.

These concerns are especially relevant for online pornography. Pornography is one of the most widely consumed forms of digital content, generating billions of visits each month globally. Since 2023, 25 US states have enacted laws requiring adult websites to verify that users are at least 18 years old, generally by requesting government-issued identification or similar information. These laws aim to reduce minors’ access to pornography, but their effects also depend on how websites and users respond to them.

Pornhub, the world’s largest adult website, blocks access for users in most states that have enacted age-verification laws. The block applies to all users, including adults and minors. Other sites have chosen to comply by restricting access to content until a user completes an age-verification procedure. By contrast, some sites have continued operating without an age-verification requirement, relying on the difficulty of enforcement.

Our research examines how these age-verification laws affected activity on adult websites. We used individual-level browsing data from approximately 550,000 US desktop and mobile internet users between 2022 and 2024. We compared changes in weekly time spent on adult websites in states before and after restrictions took effect with changes in other states. This allowed us to separate changes related to the laws from broader shifts in internet use or pornography consumption.

Our findings reveal that age-verification laws reduced overall time spent on adult websites, but these effects were muted by users circumventing blocks and switching to noncompliant websites. Four to eight weeks after Pornhub blocked access, total time spent on adult websites fell by roughly 8 percent in the affected states. Pornhub use fell by 54 percent, meaning nearly half of prior use remained after the shutdown. This persistence suggests that users employed VPNs to continue accessing the site. We also found that credit card spending at online VPN providers increased after Pornhub blocked access.

The limited overall reduction reflects widespread noncompliance and substitution. For every 100 hours previously spent on the top 25 adult websites, users continued to spend about 50 hours on noncompliant sites. Of the remaining 50 hours, 30 hours persisted through circumvention, 10 hours shifted from compliant to noncompliant sites, and 10 hours were no longer spent on adult websites. We found no meaningful shifts toward smaller adult websites outside the top 25. For purposes of our analysis, we classified all continued use of compliant websites as circumvention because our data could not distinguish VPN use from access following successful age verification. We expect age-verified use to account for very little of this activity. Pornhub blocked access completely in the states we studied and accounted for the vast majority of time spent on compliant sites in our data.

These findings show why measuring the impact of age-verification laws on a single website can be misleading. Other large websites, including XVideos and XNXX, remained available and received more traffic after Pornhub blocked access. The overall change in adult-website use was therefore much smaller than the change on Pornhub alone. This substitution may be a downside of regulation. Pornhub has taken steps to reduce illegal and abusive content on its platform, including content involving nonconsensual activity and child sexual abuse, and has emphasized verification procedures intended to reduce the risk of abusive content being uploaded. If users instead migrate to less compliant competitors, the regulation could shift activity toward platforms with fewer safeguards rather than substantially reducing exposure to harmful content.

These patterns appeared across a broad range of users and devices. We found evidence of circumvention and substitution among all groups we examined, including young adults and users on both mobile and desktop devices. Our dataset does not include minors, so we cannot directly determine how the laws affected the group they were designed to protect. Evidence from young adults and from households with children pointed in different directions, leaving the effects on minors uncertain. Furthermore, our dataset is not perfectly representative of all US internet users and does not observe private-browsing modes, such as Google Chrome’s incognito mode.

Ultimately, our findings suggest that the design and enforceability of online regulations matter greatly for their effectiveness. Age-verification laws reduced adult-website use, but technological circumvention and noncompliant alternatives substantially limited their effectiveness. Policymakers should examine users’ practical opportunities to evade a rule or switch to noncompliant platforms.

Note
This research brief is based on Matthew Brown et al., “Can Online Activity Be Regulated? Evidence from Adult Websites,” National Bureau of Economic Research Working Paper no. 35322, June 2026.