How to fix page speed warning on BigCommerce

Steps for BigCommerce

1. Stencil theme: In your BigCommerce admin go to Storefront > My Themes and ensure you are on a Stencil-based theme (not Blueprint) — Stencil themes are optimized for Core Web Vitals and support modern asset pipelines.
2. Images: In the BigCommerce admin go to Products and re-upload product images at their correct display resolution. BigCommerce automatically serves images via Akamai CDN; use the ?imbypass=on URL parameter to verify CDN delivery is active.
3. Script manager: Go to Storefront > Script Manager and remove any third-party scripts (chat widgets, social pixels) you no longer need. For remaining scripts, set placement to 'Footer' and set load method to 'Defer' or 'Async'.
4. Page Builder: Go to Storefront > Page Builder, edit your homepage, and remove unused content sections (large hero banners with unoptimized images are the #1 BigCommerce speed killer). Replace large background images with WebP versions uploaded via Marketing > Image Manager.
5. Apps: Go to Apps > My Apps and uninstall apps you are not actively using — each app may inject storefront JavaScript.
6. Speed app: Consider installing a performance app from the BigCommerce App Marketplace (search 'page speed') for automated lazy loading and script management.

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.