5 Custom WordPress Code Snippets to Speed Up WooCommerce (No Plugins Needed)

1. Dequeue WooCommerce CSS/JS on Pages That Don't Need It

WooCommerce loads its core stylesheets and scripts on every single page by default — your homepage, blog posts, even a plain "About Us" page get the full cart/checkout CSS and JS bundle whether a product is on screen or not. That's dead weight on every page load outside the shop itself.

Where to insert: functions.php

add_action( 'wp_enqueue_scripts', 'dn_dequeue_woocommerce_assets', 99 );
function dn_dequeue_woocommerce_assets() {
    if ( is_woocommerce() || is_cart() || is_checkout() || is_account_page() ) {
        return; // keep WooCommerce assets on pages that actually need them
    }
    wp_dequeue_style( 'woocommerce-general' );
    wp_dequeue_style( 'woocommerce-layout' );
    wp_dequeue_style( 'woocommerce-smallscreen' );
    wp_dequeue_script( 'woocommerce' );
    wp_dequeue_script( 'wc-add-to-cart' );
    wp_dequeue_script( 'wc-cart-fragments' );
}

Step-by-step:

1. Paste the snippet into functions.php.
2. Open a non-shop page (e.g., a blog post) in an incognito window and check the Network tab in DevTools — the WooCommerce CSS/JS files should no longer load.
3. Visit a product page, the cart, and checkout to confirm those still load everything correctly — this condition list (is_woocommerce(), is_cart(), etc.) is what protects them.
4. If your theme shows a mini-cart widget in the header on every page (not just shop pages), skip this snippet or add that widget's required scripts back to the exception list — otherwise the mini-cart will stop working outside the shop.

2. Tame Cart Fragments — the Silent AJAX Request on Every Page

By default, WooCommerce fires an admin-ajax.php request on every page load to keep the mini-cart count in sync (this is what powers the "1 item in cart" badge updating without a refresh). On a busy site, this is a constant stream of uncached AJAX calls hitting PHP — measurable overhead multiplied across every single visitor and page view.

Where to insert: functions.php

// Full removal — use only if you don't rely on a live-updating
// mini-cart count anywhere in your theme.
add_action( 'wp_enqueue_scripts', function () {
    wp_dequeue_script( 'wc-cart-fragments' );
}, 11 );

Step-by-step:

1. Before pasting this, check whether your theme's header shows a cart icon with a live item count that updates without a page reload — if it does, this snippet will freeze that count until the next full page load.
2. If you don't rely on that live update (many themes just show the count from the page's own render), paste the snippet into functions.php.
3. Add a product to your cart from a product listing page, then check the header cart icon — if it doesn't update instantly but does after navigating to a new page, the snippet is working as expected.
4. Open DevTools → Network → filter by admin-ajax.php and reload a few pages — you should no longer see the automatic wc-ajax=get_refreshed_fragments request firing on load.

3. Shrink the "Related Products" Query on Product Pages

The "Related Products" section at the bottom of a product page runs its own database query, and by default WooCommerce pulls more candidates than it actually displays before filtering them down. On stores with a large catalog, this query gets noticeably heavier — trimming the pool it searches through speeds up every single product page.

Where to insert: functions.php

add_filter( 'woocommerce_output_related_products_args', function ( $args ) {
    $args['posts_per_page'] = 3; // how many related products to actually show
    $args['columns']        = 3; // how many columns to display them in
    return $args;
} );

Step-by-step:

1. Paste the snippet into functions.php.
2. Change posts_per_page and columns to match how many related products you actually want shown — they don't have to match each other, but for a clean grid it usually looks best if they do.
3. Open any product page and scroll to the Related Products section to confirm the new count.
4. If you want to remove the section entirely instead of shrinking it, set $args['posts_per_page'] = 0; instead.

4. Shorten WooCommerce's Session Lifetime

WooCommerce stores a session row for every visitor who so much as views a product or adds something to their cart — including guests who never come back. By default, these sessions live for 48 hours, which means a busy store can accumulate a large number of session rows in the database at any given time, most of them abandoned. Shortening the lifetime keeps that table leaner and its queries faster.

Where to insert: functions.php

// Show the "your session is expiring" notice after 6 hours instead of the default.
add_filter( 'wc_session_expiring', function ( $seconds ) {
    return HOUR_IN_SECONDS * 6;
} );
 
// Fully expire abandoned sessions after 8 hours instead of the default 48.
add_filter( 'wc_session_expiration', function ( $seconds ) {
    return HOUR_IN_SECONDS * 8;
} );

Step-by-step:

1. Paste the snippet into functions.php.
2. Adjust the hour values to fit your store — a site with a long average checkout time (multi-day B2B orders, for example) should keep this longer; a fast-turnover retail store can safely go shorter.
3. These settings only affect new sessions created after you add the snippet — existing sessions keep their original expiration.
4. To see the effect on database size, check your wp_woocommerce_sessions table row count a few days before and after making this change.

5. Disable Unused Product Gallery Zoom, Lightbox & Slider Scripts

WooCommerce's default product gallery loads three separate JavaScript features on every single product page: image zoom on hover, a lightbox popup, and a touch slider — even if your theme overrides the gallery entirely or you never use these interactions. Each one is extra JS parsed and executed for nothing.

Where to insert: functions.php

add_action( 'wp_loaded', function () {
    // Comment out any line below for a feature you actually want to keep.
    remove_theme_support( 'wc-product-gallery-zoom' );
    remove_theme_support( 'wc-product-gallery-lightbox' );
    remove_theme_support( 'wc-product-gallery-slider' );
} );

Step-by-step:

1. Open a product page first and check whether you actually use image zoom, the lightbox popup, or the swipe slider — if customers rely on any of these, keep that specific line commented out.
2. Paste the snippet (with only the lines you want) into functions.php.
3. Reload a product page and confirm the gallery still displays images correctly — removing these features only disables the extra interaction, not the images themselves.
4. Check DevTools → Network again to confirm the corresponding JS files (like zoom.min.js or photoswipe.min.js) no longer load.

A Note on Measuring the Difference

Run a before/after comparison with a tool like Google PageSpeed Insights or GTmetrix on a product page and a non-shop page — the biggest visible win usually comes from snippet #1 (fewer assets loading site-wide) and #2 (one less AJAX request per page). Snippets #3 through #5 matter more as your catalog and traffic grow, since their savings compound with product count and visitor volume rather than being felt immediately on a small store.

Want these as ready-to-copy cards with a live preview instead of scrolling through a blog post? Check the WooCommerce Essential Snippets category in our WordPress Snippet Generator.