Google Chrome 76, scheduled to roll out on July 30, will fix a loophole that allows websites to detect visitors who are Incognito Mode, a move that will affect how publishers implement paywalls for their content.
In a blog post, Google said that some websites have been taking advantage of an unintended loophole involving Chrome’s FileSystem API. When in Incognito Mode, the API is disabled so that people will not leave traces of activity. Websites have been checking for the availability of the API, and if they do not find it, they determine that Incognito Mode is activated.
In Chrome 76, the behavior of the FileSystem API will be changed to prevent the Incognito Mode detection. Google also expressed its commitment to the principles of private browsing by saying that it will fix any other means of Incognito Mode detection.
The fix, which was first flagged in February, will impact publishers, particularly those who assume that users on Incognito Mode are trying to bypass metered paywalls. The Boston Globe started blocking visitors in Incognito Mode in 2017, requiring users in private browsing to log in to paid subscriber accounts to gain access to the website. The New York Times, Los Angeles Times, and other newspapers followed suit.
Ars Technica confirmed with Chrome 76 beta that the Boston Globe, the New York Times, and the Los Angeles Times were unable to detect that the browser was in Incognito Mode, unlike with Chrome 75.
Google acknowledged that the move will complicate matters for publishers who are enforcing paywalls, with many news websites limiting readers without subscriptions to a limited number of free articles per month. Incognito Mode, however, may bypass these limitations.
Google said that metered paywalls are “inherently porous,” as it requires cookies to track the number of free articles that a user has viewed. The company suggested options to news websites that include reducing the number of free articles, requiring free registration to view content, and hardening paywalls. Google added that publishers should take a look at the effect of the FileSystem API fix before making any changes to their websites.
“Our News teams support sites with meter strategies and recognize the goal of reducing meter circumvention, however any approach based on private browsing detection undermines the principles of Incognito Mode,” said Google.