Google is making a change to “remedy a loophole” that allowed sites to detect people who are browsing in Incognito Mode on Google Chrome.

The search engine giant says it is based on the principle that every web user should have the right to browse the web privately if they wish, however, the changes will impact publishers that try to enforce metered paywalls on their content.

Previously the ‘FileSystem API loophole’ allowed sites to detect users even if they were in Incognito Mode, allowing publishers to stop people from avoiding metered paywalls and forcing them to sign in.

The ‘metered’ or ‘soft’ paywall approach gives readers access to a limited number of free articles before they are asked to sign up.

Nine’s The Sydney Morning Herald is just one publisher that enforces such an approach.

By closing this loophole, publishers will no longer be able to identify readers in Incognito Mode.

While acknowledging the changes will impact publishers, Google defended the change by questioning the effectiveness of metred paywalls.

“Unlike hard paywalls or registration walls, which require people to log in to view any content, meters offer a number of free articles before you must log in,” said Google partner development manager, news and web partnerships Barb Palser.

“This model is inherently porous, as it relies on a site’s ability to track the number of free articles someone has viewed, typically using cookies.

“Private browsing modes are one of several tactics people use to manage their cookies and thereby “reset” the meter count.”

Palser suggested publishers consider reducing the number of free articles someone can view before logging in, requiring free registration to view any content, or hardening their paywalls if they wish to deter meter circumnavigation.

The change will come into effect on 30 July.