Website pop-ups: do they hurt conversions or your SEO?

A pop-up can help or hurt, and the difference is mostly timing, size and how easy it is to close. Google says pop-ups that cover your content may lead to poor search performance. Experiments suggest people mind less when a pop-up appears late or when they ask for it.

So you can use one, but keep it small, delay it, make it easy to close, and test it on a real phone. Below we explain what the evidence says, where it runs out, and what to use instead.

Should a small business use a pop-up at all?

A pop-up trades irritation for attention. It gets a message in front of everyone, including people who were not looking for it. Some will sign up. Others will leave or feel a little less trust in you.

Google's own guidance says interrupting users may frustrate them and erode their trust. That is the cost to weigh against the extra sign-ups.

We found no UK data on how people feel about pop-ups, and no large independent dataset of pop-up conversion rates. Figures quoted in plugin vendors' blogs are not primary data, so we have not used them. Results vary by site. Test your own.

What Google actually says

In 2016, Google announced that from 10 January 2017, pages where content is not easily accessible after arriving from mobile search may not rank as highly. Note the wording: "may not". It is not a guaranteed penalty.

The same announcement named three patterns to avoid:

• A pop-up that covers the main content.
• A standalone interstitial that people must dismiss before they see the page.
• A layout that looks like an interstitial, with the real content pushed below the fold.

What is acceptable

Google treats some things as fine. These are cookie and age-verification notices, login dialogs on non-public content, and easily dismissible banners that use a reasonable amount of screen space. If you only need a consent notice, see our guide to the cookie banner in the UK.

Google's current documentation says intrusive interstitials and dialogs may lead to poor search performance. It advises banners that take up only a small fraction of the screen, and says those same small containers can be reused for newsletter sign-up prompts.

You may see blogs claiming a pop-up must cover under 30% of the screen, or wait 10 seconds. Google does not give numbers like these, so treat them as guesses.

What experiments show about irritation

Timing matters. In a lab experiment, people's eyes fixated for significantly longer, and more often, on a pop-up ad that appeared after 20 seconds than on one that appeared immediately. The authors say delaying it until after reading reduces how intrusive it feels.

Click-triggered pop-ups look promising too. In a small prototype shop test with 13 users, click-triggered "polite" pop-ups were mostly noticed and users chose to open the information inside them. That is a tiny sample, so take it as a hint only.

There is a cost to interruptions as well. An older experiment found people shown in-line ads remembered about 3.4% more of the site's material than people shown pop-up ads.

These studies looked at ads and prototypes, not your sign-up form. They point in a direction. They do not give you a rule.

Is there a conversion sweet spot?

One real-environment experiment raised the intensity of marketing elements step by step. The group with a moderately more intense design reached a 3.44% conversion rate, which was 35% higher than the comparison group. Further increases produced a negative response and no extra conversions.

The lesson is to nudge, not shove. A clear offer, shown once, at a sensible moment, beats a pop-up that is large, repeated and hard to dismiss. This is a preprint from one study, so use it as a guide for what to test.

Wording counts as well. A "no thanks" button that makes people feel guilty puts them off.

Pop-ups that break the page

A pop-up or banner can also make the page jump. Google says sites should aim for a layout shift score (CLS) of 0.1 or less for at least 75% of page visits, and anything above 0.25 is poor. It warns that banners and forms inserted without reserved space shift page content.

This is common. HTTP Archive data show about a quarter of sites do not meet the recommended CLS threshold. Pages that animate layout-affecting CSS properties are 15% less likely to have good CLS, and the same page names cookie and notification banners that slide in as a common cause.

• Reserve space for a banner so the page does not move when it appears.
• Avoid sliding animations that push content down.
• Prefer an overlay that sits on top of the page to one that shoves text lower.

Slow pages and jumpy pages go together. Our guide on how fast a website should load covers the targets.

Accessibility: can everyone close it?

A pop-up that some people cannot close is a barrier, not a nuisance. Two WCAG 2.2 rules matter most.

Success criterion 1.4.13 (Level AA) says content that appears on hover or focus must be dismissible without moving the pointer or focus. Its examples include custom tooltips and other non-modal pop-ups.

Success criterion 2.4.11 (Level AA) says a component with keyboard focus must not be entirely hidden by content you added. W3C lists a sticky footer or header completely hiding focused elements as a failure.

In practice, check these:

• The close button is large, clearly marked and reachable with the Tab key.
• The Esc key closes the pop-up.
• Keyboard focus moves into the pop-up when it opens and returns to the page when it closes.
• Sticky bars and chat bubbles do not cover buttons or form fields.

For the legal side, read our guide to website accessibility in the UK, or run our accessibility checker.

A five-minute pop-up audit and safer alternatives

The audit

1. Find your site in Google on your phone. Tap the result, as a new visitor would.
2. Note what happens in the first five seconds. Can you read the page, or does something cover it?
3. Try to close any pop-up with your thumb. Is the close button easy to hit?
4. Scroll. Do sticky bars or chat bubbles hide your buttons?
5. Open the site on a laptop and use only the keyboard. Can you close the pop-up with Esc, and can you see where focus is?
6. Clear your cookies, or use a private window, and check how often it comes back.

Safer alternatives

• An inline sign-up form in the page or footer. It never blocks anything.
• A slim banner at the top or bottom, in line with Google's advice on small banners.
• A button that opens a dialog when someone clicks it, such as "Get 10% off".

When not to bother

If your site gets little traffic, a pop-up will produce few sign-ups, and a clear button or form on the page may do more. If people leave without enquiring, fix the basics first. Our guides on visitors but no enquiries and high bounce rate are a good start.

AgoraScan's free website check gives you a score and the top problems, with screenshots, in about 2 minutes, including pop-ups that block the page. A full audit lists every issue with the fix.

Questions people ask

Are pop-ups bad for SEO?

They can be. Google says intrusive pop-ups and interstitials may lead to poor search performance, and pages with content that is hard to reach from mobile search may not rank as highly. It is not a guaranteed penalty, and small, easily dismissed banners are acceptable.

Do cookie banners count as intrusive pop-ups?

Google lists cookie and age-verification interstitials as acceptable. You should still make them easy to use and keep them from covering the page. Our cookie banner guide covers the details.

When should a newsletter pop-up appear?

Google gives no set delay. One lab experiment found a pop-up that appeared after 20 seconds drew longer attention than one shown immediately, and the authors say delaying it reduces how intrusive it feels. Test a delay or a click-triggered option on your own site.

Are pop-ups an accessibility problem?

They can be. People must be able to close them with a keyboard, and sticky elements must not hide the item that has focus. WCAG 2.2 sets rules on both.

Sources

1. Helping users easily access content on mobile, Google Search Central Blog (2016)
2. Avoid intrusive interstitials and dialogs, Google Search Central
3. Pop-up ad timing experiment (Hsieh et al.), Peer-reviewed experiment, hosted on gwern.net (2020)
4. Marketing element intensity experiment, arXiv preprint (2019)
5. Polite pop-ups in a prototype e-commerce test, University West and Reykjavík University, conference paper (2020)
6. A Study of the Effects of Online Advertising: A Focus on Pop-Up and In-Line Ads (McCoy et al.), Peer-reviewed experiment, mirror on academia.edu (2004)
7. Optimize Cumulative Layout Shift, web.dev (Google)
8. The most common Core Web Vitals issues, web.dev (Google)
9. Web Content Accessibility Guidelines (WCAG) 2.2, W3C (2023)
10. How to Meet WCAG 2.2 (Quick Reference), W3C (2023)