How to Use Google PageSpeed Insights to Evaluate Your Shopify Store’s Performance

PageSpeed Insights is one of the most accessible performance diagnostic tools available — and one of the most useful for Shopify merchants who want to understand why their store might be loading slowly.

How to run a test

Go to pagespeed.web.dev, enter your store URL, and click Analyze. The tool will take a minute or two to run, especially on larger stores. Once complete, you’ll see scores across four categories: Performance, Accessibility, Best Practices, and SEO.

Reading your scores

Scores are color-coded: green (90-100) is good, yellow (50-89) needs improvement, and red (0-49) needs attention. Mobile and desktop scores are reported separately — always check both, but prioritize mobile given where most e-commerce traffic comes from.

What the performance score actually measures

The performance score is based on Core Web Vitals — Google’s standardized metrics for user experience. The ones that matter most are Largest Contentful Paint (how quickly the main content loads), Interaction to Next Paint (how responsive the page feels), and Cumulative Layout Shift (how much the page jumps around as it loads).

Common issues on Shopify stores

Large uncompressed images are the most frequent culprit. Render-blocking JavaScript from third-party apps is another — every app you install adds load time. Unused CSS and JavaScript, slow server response times, and improperly sized images for mobile all show up regularly.

What to do with the results

The tool provides specific recommendations prioritized by impact. Work through them in order, starting with the ones flagged as having the highest potential improvement. After making changes, clear your store’s cache before retesting so PageSpeed Insights is evaluating the latest version of your code.