Apr 15, 2026 13:00:00

Google has announced it will punish 'back button hijacking' as spam.

Google has formulated a new anti-spam policy stating that when a user presses the browser's 'back' button, it should perform the action they expect: 'return to the previous page.'

Introducing a new spam policy for 'back button hijacking' | Google Search Central Blog | Google for Developers

https://developers.google.com/search/blog/2026/04/back-button-hijacking

A new paragraph has been added to the English version of 'Google Web Search Spam Policy'.

The following is the translation into Japanese:

'Back button hijacking refers to the act of a website manipulating browser history or other data to interfere with a user's navigation, preventing them from immediately returning to the previous page even when they press the 'back' button.'

Browsers have a '

History API ' that allows websites to manipulate user history. The History API allows websites to freely add to a user's history, and it is intended to be used in single-page applications that 'make it appear as if the screen has moved without actually changing pages,' enabling the browser's 'back' function. When history is added using the History API, pressing 'back' will not actually cause a page transition.

Furthermore, when a user presses the 'back' button, an event called 'popstate' is triggered. By using this event as a trigger to run a process, it is possible to implement a single-page application that 'makes it appear as if the user has moved to a different page, even though they haven't actually moved.'

By exploiting these APIs, it's possible to, for example, 'secretly add the same URL once to the history of users who have accessed the site,' thereby disabling the first 'back' click. Then, by writing code that displays an ad triggered by popstate, it's possible to 'display an ad instead of returning to the previous page when the 'back' button is pressed.'

Of course, from the user's perspective, it is unpleasant to have a different action performed when they press 'back,' and this degrades the user experience. Google emphasizes that 'user experience is our top priority' and states that 'inserting manipulative pages into a user's browser history always goes against the fundamental principles of Google Search' as the reason for classifying it as spam.

A new policy prohibiting the hijacking of the back button is scheduled to go into effect on June 15, 2026. Websites that have implemented mechanisms that degrade the user experience through their back button after the policy goes into effect may face measures such as manual exclusion from search results or automatic ranking downgrades.

Please note that GIGAZINE does not have ad slots that hijack the back button, but malicious advertisers may circumvent regulations and deliver ads that hijack the back button without permission. To stop such ads, if you see any such malicious ads on GIGAZINE, please immediately report them in the form at the bottom of the page, checking the box that says 'Please check this box if this is a report about a link malfunction or fraudulent ad.' GIGAZINE has had its own community for combating spam ads for over a year now and is taking measures to address this issue.