An interstitial popup is a full-screen or large overlay that appears on a web page and interrupts the user’s experience before they can access the main content they came to see. Unlike smaller, less intrusive popup formats, such as corner banners or slide-in notifications, an interstitial covers a significant portion or the entire page, requiring the user to actively dismiss it before they can proceed.
The term “interstitial” comes from the Latin for “in between,” reflecting the fact that these elements insert themselves between the user and the content they are trying to reach.
Interstitials are widely used because they are highly effective at capturing user attention and driving specific actions. However, their effectiveness at capturing attention comes at the cost of user experience, as they create friction and delay access to content.
There are broadly two categories of interstitial:
- Intrusive interstitials — large overlays that cover the main content and are difficult or impossible to dismiss without completing an action or actively seeking out a close button, providing a poor user experience, particularly on mobile devices
- Acceptable interstitials — overlays that Google considers reasonable and does not penalise, including those required by law or serving a legitimate purpose
Google considers these acceptable interstitials :
- Cookie consent notices and privacy policy acknowledgements that are required by law
- Age verification gates for content restricted to adults, such as alcohol or gambling sites
- Login prompts for content that is genuinely private or paywalled, such as subscriber-only articles
Examples of intrusive interstitials:
- A full-screen email sign-up popup that appears immediately when a user lands on a page from search results
- An overlay that covers the main content and cannot be easily dismissed
- A layout where the interstitial appears above the fold and the actual content is pushed below, making it appear to the user that the page content is the interstitial itself
In January 2017, Google introduced a mobile interstitial penalty, which is a specific ranking demotion for pages that display intrusive interstitials to mobile users arriving from Google Search. The rationale was straightforward: if a user clicks on a search result and is immediately confronted with a large popup before they can access the content they were looking for, the experience falls short of what Google wants to reward.
Pages that use intrusive interstitials on mobile may therefore be ranked lower than equivalent pages that do not, directly impacting organic visibility. Beyond the direct ranking penalty, intrusive interstitials can also increase bounce rates, where if users find the popup annoying or cannot easily dismiss it, they may simply hit the back button and return to the search results, sending a negative engagement signal. Balancing the conversion benefits of interstitials against their impact on user experience and SEO is an important consideration, and where popups are used, ensuring they are easy to dismiss, do not cover the main content excessively, and comply with Google’s guidelines is essential.
