An intrusive interstitial is a pop-up, overlay or full-screen panel that covers the main content of a page so the visitor cannot read what they came for without dismissing it. Google has treated these as a poor page experience on mobile since 2017, and they remain part of its page experience guidance.
How intrusive interstitials work
The word interstitial means something that sits in between, in this case between the visitor and the content. Google’s examples of the intrusive kind are:
- A pop-up that covers the main content as soon as someone arrives from search, or while they scroll.
- A standalone panel the visitor must close before reaching the content, such as a full-screen newsletter offer.
- A layout where the top of the screen looks like a pop-up and the real content has been pushed below the fold.
Google also lists exceptions. Overlays that are there because the law requires them, such as cookie consent and age verification, are not treated as intrusive provided they are a reasonable size. Login boxes for content that is not publicly indexable are fine. So are banners that take up a modest slice of the screen and are easy to dismiss.
Why it matters
For UK sites the cookie question comes up first. A cookie banner that meets UK GDPR and PECR requirements falls within Google’s exemption for legally required interstitials. The ICO expects real choice, so the banner has to be noticeable, but that does not mean it should fill the whole phone screen. A bottom bar or a compact panel with clear “Accept” and “Reject” buttons satisfies the law and stays well clear of the intrusive category.
The problems usually come from marketing pop-ups stacked on top. A visitor from Google opens a recipe page on their phone, dismisses the cookie banner, and is immediately hit with a “10% off your first order” panel covering everything. Many simply press Back and choose the next result, which is the behaviour this guidance is designed to discourage.
Common mistakes
- Firing a sign-up pop-up the instant the page loads. The visitor has not read a word yet, so they have no reason to subscribe.
- Stacking overlays. Cookie banner, then discount offer, then chat widget, all within seconds.
- Tiny or hidden close buttons. On a phone, a close cross smaller than a fingertip is effectively a trap, and people blame the brand.
- A full-screen cookie wall. Making the whole page unusable until someone consents can be both intrusive and, under ICO guidance, a consent problem in its own right.
- Testing on desktop only. A pop-up that looks small on a laptop can cover the entire screen of a phone.
How to act on it
Open your key landing pages on a real phone, arriving from a Google search rather than typing the address, and note everything that appears before you can read the content. That is the experience Google is judging.
Keep the cookie banner compact and remove any other overlay that appears on arrival. Replace timed pop-ups with inline sign-up boxes within the content, a slim banner, or an exit-intent pop-up on desktop only. If you rely on pop-ups for lead capture, compare sign-ups before and after the change; inline forms often hold up better than expected because the people who use them have read the page first.
Pop-ups and banners are part of the wider page experience picture alongside speed and mobile usability, which I review as part of technical SEO.