A Google mobile-friendly test checks how easily visitors can use your website on a phone. Google retired its mobile-friendly test tool in December 2023, but everything it measured—including factors like text readability and site loading speed—still shapes how your site performs in Google search and how easily people can buy from your store on mobile.
The umbrella brand Original Duckhead rebuilt their site around mobile. On an episode of the Shopify Masters podcast, founder Morgan Cros describes what changed, saying, “We used to design our website from the standpoint of looking at it from a computer screen, but that’s not how people shop anymore, and so that change made a big difference in our revenue and our conversion rate.”
Here’s what a Google mobile-friendly test involves, why it matters for search engine optimization (SEO), and how to test and improve your website’s mobile performance.
What is a Google mobile-friendly test?
A Google mobile-friendly test assesses how well a site performs on mobile phones and other smaller devices. The original tool, launched by Google in 2014, involved entering a URL and getting an analysis of the page’s mobile performance. Google now recommends using Lighthouse for a similar audit.
The Mobile Friendly test scored URLs on a handful of factors, and those still determine whether a site works well on a small screen:
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Viewport configuration. This is how well a page adapts to the width of the device’s screen. Responsive design allows your website to do this automatically.
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Text readability. Font size and contrast determine whether someone can read the page on a small screen without zooming in.
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Touch element spacing. Buttons, links, and other touch elements like form fields need to be large enough and spaced far enough apart for you to tap them with your thumb.
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Loading speed. This is a measure of how quickly a page renders on a mobile device. Pages with large or slow-loading elements like uncompressed videos, oversized images, and unused scripts may load slowly, which affects user experience.
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Content width. To be mobile-friendly, your pages should fit a narrow screen without forcing the reader to scroll sideways.
Why mobile-friendliness matters for SEO
A website’s mobile performance is an important part of SEO, and it can impact how shoppers engage with your store. Here’s why mobile-friendliness matters:
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Search rankings. Google uses mobile-first indexing, which means your mobile pages—not your desktop ones—are the version it crawls, indexes, and ranks in search engine results pages (SERPs). Because mobile usability is part of Google’s page experience guidelines, a page that’s hard to use on a phone can rank below competitors with better usability.
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Consumer preference. In the first quarter of 2026, smartphones accounted for roughly three-quarters of US retail website visits and two-thirds of online shopping orders, according to Statista. Mobile optimization is now the baseline for ecommerce, which means your product pages, site navigation, and checkout experience need to work well on mobile devices.
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User experience. A fast-loading, responsive, and readable mobile website is easier to navigate and use. A 2025 report by Contentsquare, based on an analysis of 90 billion sessions, found that slow-loading content was a key contributor to bounces, causing 53% of visitors to leave after viewing a single page.
How to test for mobile-friendliness
- Choose the tools you’ll use
- Review your results and prioritize fixes
- Preview and adjust your site on mobile
- Keep checking as your site and Google’s guidance change
Use this step-by-step guide to make your website more mobile-friendly:
1. Choose the tools you’ll use
There are several alternatives to Google’s original mobile-friendliness test. Lighthouse is the audit engine Google recommends. The Core Web Vitals report in Google Search Console reports what real visitors experienced across your site. PageSpeed Insights combines the two on one page.
Here’s how they compare:
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Lighthouse. This open-source tool is Google’s recommended replacement for its retired test. It scores your website out of 100 on performance, accessibility, best practices, and SEO, and provides recommendations for site improvement. Lighthouse is built into the developer tools in the Chrome browser, so there’s nothing to install, though you can also run it from the command line.
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Core Web Vitals report.Core Web Vitals report what real Chrome users experience across your site over the past 28 days. It grades your URLs as good, needs improvement, or poor based on how quickly the main content loads, how quickly the page responds to a tap, and how much the content jumps while loading. It groups similar pages together, so it shows you which templates are causing problems rather than specific URLs.
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PageSpeed Insights. This browser-based version of the Lighthouse audit also reports the three Core Web Vitals, plus a performance score out of 100. Lighthouse’s scoring documentation grades 0 to 49 as poor, 50 to 89 as needs improvement, and 90 to 100 as good.
You don’t need to use all three tests. The best tool or combination depends on how much detail you want and how familiar you are with performance data. PageSpeed Insights is the simplest starting point because it runs the Lighthouse audit for you in the browser and reports Core Web Vitals alongside recommendations. There’s nothing you need to install or configure.
Running Lighthouse directly in Chrome’s developer tools gives you the same audit with more detail, which is useful if you’re comfortable using developer tools or working with a developer. The Core Web Vitals report gives you insight into what real visitors did. It requires an understanding of its listed metrics: Largest Contentful Paint, Interaction to Next Paint, and Cumulative Layout Shift.
2. Review your results and prioritize fixes
Once you have a picture of your website’s mobile performance, decide what to fix first. Start with high-traffic pages, such as a landing page or hero product page, and with steps that are important for conversion, like the checkout process.
Group your mobile-friendliness issues by the effort involved in addressing them. Fixing broken links, compressing oversized images, and removing unused apps or scripts are quick wins that you can do yourself. Other issues—like cluttered navigation or a slow theme—might need more planning or developer resources.
3. Preview and adjust your site on mobile
Some mobile optimization is handled for you, depending on the platform you use. With Shopify, server configurations and CDN setup are built in, and themes are responsive out of the box.
If your site is already live, open it on an actual phone or tablet and test out key actions like adding items to your cart and completing a purchase. Check whether anything obscures your page content, like promotional pop-ups that consume much of the screen. You can also use your desktop browser’s device emulation view (available in developer tools) to see how your layout appears on different screen widths.
Some hosting platforms also come with a mobile preview built in. On Shopify, switch the theme editor to mobile view in your store admin. You can edit your mobile layout—for example, changing image ratios, text alignment, and the number of products that appear per row—without changing your desktop design.
4. Keep checking as your site and Google’s guidance change
Review your site after making theme changes, installing new apps, or launching a major campaign (like a new seasonal collection). These changes can impact your site’s mobile-friendliness, and catching any issues early can help you preserve the user experience for mobile shoppers.
Mobile optimization best practices also evolve as Google updates its page experience guidelines. You can find that guidance in Google Search Central, the SEO documentation hub for site owners.
Google mobile-friendly test FAQ
Is there a specific Google mobile-friendly test?
Google retired its mobile-friendliness test in December 2023, but other tools cover similar ground. Current options include Lighthouse, PageSpeed Insights, and the Core Web Vitals report in Google Search Console.
Does mobile-friendliness affect SEO rankings?
Yes, mobile-friendliness can affect site rankings. Google uses mobile-first indexing, which means it crawls and ranks the mobile version of your pages. Mobile usability is also part of Google’s page experience guidance, and a page that’s slow or awkward to use on mobile can rank lower than competitors with a better mobile experience.
What’s the difference between responsive and mobile-friendly?
A responsive site automatically adapts its layout, images, and navigation to different screen sizes. A mobile-friendly site is easy to read and use on mobile devices, but this can be achieved in different ways, including a dedicated mobile version or a simplified version of the website. A site doesn’t need to be responsive to be mobile-friendly, though responsive design is a common approach.
