How to fix page speed warning on PrestaShop

Steps for PrestaShop

1. In the PrestaShop admin go to Advanced Parameters > Performance: set 'Smart cache for CSS' and 'Smart cache for JavaScript' to Yes, enable CCC (Combine, Compress, Cache) for both CSS and JS, and set 'Minimize HTML' to Yes.
2. Enable 'Use CCC for CSS files', 'Use CCC for JavaScript files', and 'Compress inline JavaScript' all from the same Performance page.
3. Images: Go to Design > Image Settings and configure WebP format output. Then go to Catalog > Products and use the 'Regenerate Thumbnails' option after changing settings to rebuild all product images at optimal sizes.
4. Caching: On the Performance page, under 'Caching', enable the file system cache. For high-traffic stores add a Memcached or Redis module from the PrestaShop Addons marketplace.
5. Modules: Go to Modules > Module Manager and disable or uninstall modules you are not using. Filter by 'Installed' to audit the full list.

What is page speed warning?

Page load time is how long it takes for a visitor's browser to fully display your store page after they click a link or type your URL. When a page takes more than 1.5–2 seconds to load, visitors experience a noticeable delay before they can see and interact with your content. A load time of 3 seconds or more (like the example finding) is considered slow by both Google and modern shoppers. Page speed is measured by several signals — the most important being Google's Core Web Vitals, which assess how fast your content appears, how quickly it becomes interactive, and how stable the layout is as it loads.

Google has officially made page speed and Core Web Vitals a direct ranking factor for all pages. Slow pages rank lower in search results, meaning fewer people find your store organically — costing you traffic and revenue before a visitor even arrives. For shoppers who do visit, studies consistently show that every additional second of load time reduces conversions: a 3-second page loses a significant portion of mobile shoppers to bounce before they see a single product. Slow stores also perform poorly in Google's mobile-first index, which evaluates your mobile experience first when deciding your rankings. Fixing page speed is one of the highest-ROI improvements an ecommerce store can make — it simultaneously boosts your SEO rankings, increases conversion rates, and improves accessibility for users on slower connections or lower-end devices.

See the complete Page speed warning guide for every platform and the full background.