WooCommerce cart speed, fixed properly.

WooCommerce cart and checkout are the two pages on your site that can't be page-cached, that customers care most about, and that fail most reliably on busy days. Every visitor is logged in, every cart is unique, every checkout fires payment SDKs, tax calculations, shipping queries and tracking scripts. The result on most stores is a cart that takes 3–6 seconds to load and a checkout that takes 5–10 seconds — and every additional second measurably reduces conversion rate.

The fix is layered. Persistent object caching with Redis is the foundation; without it every cart action triggers 100+ database queries that run from scratch. With Redis, query results are cached in memory and reused, typically cutting cart database load by 70%. Then we disable cart fragments AJAX — WooCommerce's habit of making an AJAX call on every page load to update the cart count in the header. On a busy site that's thousands of requests per minute hammering admin-ajax.php for no benefit. A cookie-based cart count replaces it with zero overhead.

On checkout we profile specifically. Address validation, shipping calculation, tax calculation, payment gateway initialisation and third-party tracking scripts all add latency. We defer payment SDKs until needed (only load Stripe.js when the customer selects card payment, not on page load), batch shipping queries, optimise tax lookups, and move tracking pixels to async. The result is a checkout that loads in 1.5–2.5 seconds instead of 5–10.

For modern WooCommerce (8.3+) we also recommend migrating to the new Block-based checkout, which is significantly faster than the legacy shortcode version — less JavaScript, fewer database queries, better caching. We handle the migration including any custom field migration and integration testing. Combined with the cart and checkout fixes, most stores see conversion lift within the first week of going live.