Google will penalise sites that serve pop-up ads on mobile in its latest attempt to declutter the web.
The firm revealed that pages with intrusive ads may rank lower in search results after the algorithm change comes into force in mid-January next year.
The search giant uses hundreds of factors to determine its rankings, so if a page appears to be more informative or relevant than others it will still rank higher.
But if two pages vying for the coveted top spot are deemed equally authoritative, the site without pop-ups will rank first.
The move forms part of a wider effort by Google to make mobile browsing more seamless.
In November last year, it launched Accelerated Mobile Pages, a service that displays stripped-back, data-light articles on mobile browsers.
The search firm also started boosting pages which classified as “mobile-friendly” and used encryption.
In a blogpost announcing the latest change, Google revealed that 85% of pages are now “mobile-friendly”, an indicator of the firm’s influence over publishers.
As revenue from traditional banner ads falters, publishers are increasingly looking for new ways of directing users’ attention to ads.
They may soon find that the extra revenue pop-ups generate is swiftly undone by the loss of traffic that comes with being bumped down the rankings.
Google clarified that banner ads which use a “reasonable” amount of the screen and are easily dismissible would not be affected.
Pop-ups that fulfil a legal requirement such as age verification and cookie consent won’t be penalised either.
The update comes as users are increasingly turning to adblockers to purge their browsers of distracting, data-thirsty adverts.
When Apple opened up iOS to adblocker developers last year, their apps instantly shot to the top of App Store rankings.