How to fix slow page on BigCommerce

Steps for BigCommerce

1. Go to Storefront → My Themes → Advanced → Edit Theme Files and review your theme's JavaScript files for bloat or synchronous loading patterns.
2. Images: Use BigCommerce's built-in Akamai Image Manager (enabled by default on most plans) — ensure you are referencing images via the CDN URL and using the 'width' and 'format=auto' query parameters to serve correctly sized WebP images.
3. In the theme's templates/layout/base.html, add defer or async to non-critical <script> tags.
4. Apps/Scripts: Go to Channel Manager → Scripts (or Storefront → Script Manager) — review every installed script and remove those not in active use.
5. Enable BigCommerce's built-in Akamai CDN (included on most plans) — confirm it is active under Store Setup → Store Profile.
6. Use Google PageSpeed Insights on your storefront URL and address each flagged resource type individually in the theme editor.

What is slow page?

Page load time is how long it takes for a visitor's browser to fully display your store page. When a page takes longer than about 3 seconds, visitors tend to leave before they even see your products — a behaviour called "bouncing." Google also directly measures loading speed as part of its Core Web Vitals scoring system, which feeds into how high your pages rank in search results. A load time of nearly 10 seconds (like the example above) is extremely slow and will hurt both rankings and sales.

Google uses Core Web Vitals — which include Largest Contentful Paint (LCP), a direct measure of loading speed — as a confirmed ranking signal. Pages that load slowly rank lower in search results, meaning fewer shoppers find you organically. Research consistently shows that every additional second of load time reduces conversion rates by roughly 4–7 %, so a 10-second page can cost you a significant share of potential sales. Slow pages also create a poor first impression, increase bounce rates, and can disqualify your pages from Google's "Page Experience" enhancements in search results. On mobile — where Google primarily indexes your site — performance issues are amplified further.

See the complete Slow page guide for every platform and the full background.