Most slow Shopify stores are caused by too many apps, large uncompressed images, heavy third-party scripts and outdated themes. Remove unused apps, compress and resize images, delay non-essential scripts and keep your theme updated to improve speed and Core Web Vitals.
A slow store costs sales, especially on mobile. Shopify’s hosting is fast, so speed problems usually come from what has been added to the store. Here are the most common causes and how to fix them.
How to measure speed
Use Google PageSpeed Insights on your homepage, a collection page and a product page. Focus on the three Core Web Vitals:
| Metric | What it measures | Good score |
|---|---|---|
| LCP (Largest Contentful Paint) | How fast the main content appears | 2.5 seconds or less |
| INP (Interaction to Next Paint) | How quickly the page responds to taps and clicks | 200 milliseconds or less |
| CLS (Cumulative Layout Shift) | How much the layout jumps while loading | 0.1 or less |
Five common causes
1. Too many apps
Each app can add its own scripts to every page. Uninstalling an app does not always remove its code from your theme. Review your apps, remove the ones you do not use, and ask a developer to clean up leftover code.
2. Large images
Upload images at a sensible size (around 2,000 px wide is plenty for most product photos) and let Shopify serve modern formats. Make sure images below the first screen are lazy-loaded.
3. Third-party scripts
Chat widgets, tracking pixels and pop-ups all add weight. Load only what you need, and delay non-essential scripts until after the page is visible.
4. Outdated or heavy themes
Older themes may not use Shopify’s newer performance features. Updating to a current Online Store 2.0 theme often improves speed on its own.
5. Sliders and autoplay video in the hero
Large carousels and background videos slow down the first screen. A single strong image usually loads faster and converts better.
A quick action plan
- Run PageSpeed Insights on three key pages and save the results.
- Remove unused apps and leftover code.
- Compress and resize your largest images.
- Replace the hero slider with one image.
- Test again and compare.
Frequently asked questions
Does store speed affect SEO?
Yes. Core Web Vitals are part of how Google evaluates page experience, and faster pages also tend to convert better.
Can I get a perfect PageSpeed score on Shopify?
A perfect score is rarely needed. Focus on passing Core Web Vitals on mobile for your most important pages.
Activebiz is a Canadian-led Shopify studio working with brands across Canada and the US. Book a consultation and we will look at your store with you.