How to Analyze a Shopify Stores Page Speed and Performance
Patrick Bushe
May 21, 2025 · 5 min read
A slow store loses shoppers, especially on phones. Testing speed takes a few minutes, and the results usually point to a handful of fixable causes. This works for your own store or one you're studying.
1. Test with PageSpeed Insights
Go to pagespeed.web.dev and enter the store's address. You get two kinds of results:
- Real-user data from Chrome users, if the store has enough visitors. This is what Google uses.
- Lab results from a single simulated visit, with a score and a list of problems.
Test the homepage, a collection page and a product page, on mobile first.
2. Read the Core Web Vitals
- LCP (Largest Contentful Paint): how fast the main image or heading appears. Aim for under 2.5 seconds.
- INP (Interaction to Next Paint): how quickly the page responds to taps and clicks. Aim for under 200 milliseconds.
- CLS (Cumulative Layout Shift): how much things jump while loading. Aim for under 0.1.
3. Check Shopify's own report
In your Shopify admin, the web performance report shows Core Web Vitals from your real visitors over time, and marks events such as app installs and theme changes, so you can see what made things slower.
Common causes on Shopify
- Apps: each one can add scripts to every page. Old apps can leave code behind after uninstalling.
- Large images: upload sensibly sized images; Shopify serves resized versions, but huge originals and too many slideshow images still cost time.
- Video backgrounds and autoplay videos on the homepage.
- Too many fonts or font weights. See font loading performance.
- Chat widgets, pop-ups and tracking pixels, which often load early.
4. See what a store runs
Shopify Theme Detector shows a store's theme and the apps and pixels it recognizes, such as review apps, page builders, chat tools and ad pixels. A long list is often the first clue to slow pages.
5. Fix in order
- Remove apps you don't use, and check for leftover code.
- Compress and resize the biggest images, starting with the first image on each page.
- Replace autoplay videos with images on mobile.
- Delay chat widgets and pop-ups until the page has loaded or the visitor scrolls.
- Test again after each change, so you know what helped.
Free Shopify themes are a fast starting point. See free Shopify themes. For help speeding up your store, see Shopify design and development.
