Swap & Save WooCommerce Downsell: A Smarter Way to Sell

Let’s learn about WooCommerce Downsell & how it can boost Conversions with smart product swaps

In eCommerce, upselling often gets all the attention—but downselling is an underrated tactic that can recover lost sales and engage price-sensitive shoppers. With WooCommerce, we can build a simple but powerful downsell mechanism using PHP and AJAX.

Let’s walk through what it is, why it works, and how to build it with code.

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What Is Downselling?

Downselling is the practice of offering a cheaper alternative when a customer hesitates or removes a product from their cart.

In WooCommerce, we can display lower-priced alternatives right inside the cart page—and let customers swap with a click.

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How to Add a Downsell Swap Feature to Your WooCommerce Cart Page

Let’s build a feature that:

• Shows cheaper product alternatives for each cart item.
• Lets users swap products using AJAX without refreshing the page.

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1. PHP: Inject Downsell Options into Cart Items

Place this in your theme’s functions.php or a custom plugin:

add_action('woocommerce_after_cart_item_name', function($cart_item, $cart_item_key) {
    $product_id = $cart_item['product_id'];
    $product = wc_get_product($product_id);
    $price = $product->get_price();

    // Get product categories
    $terms = get_the_terms($product_id, 'product_cat');
    if (empty($terms) || is_wp_error($terms)) return;

    $term_ids = wp_list_pluck($terms, 'term_id');

    // Query cheaper products in the same category
    $args = [
        'post_type' => 'product',
        'posts_per_page' => 3,
        'post__not_in' => [$product_id],
        'meta_query' => [[
            'key' => '_price',
            'value' => $price,
            'compare' => '<',
            'type' => 'NUMERIC'
        ]],
        'tax_query' => [[
            'taxonomy' => 'product_cat',
            'field' => 'term_id',
            'terms' => $term_ids
        ]]
    ];
    $query = new WP_Query($args);
    if (!$query->have_posts()) return;

    echo '<div class="downsell-products">';
    echo '<strong>Cheaper alternatives:</strong>';
    foreach ($query->posts as $alt_post) {
        $alt_id = $alt_post->ID;
        $alt_product = wc_get_product($alt_id);
        $alt_price = wc_price($alt_product->get_price());
        $savings = wc_price($price - $alt_product->get_price());

        echo "<button 
            class='swap-product-btn' 
            data-original='{$product_id}' 
            data-alt='{$alt_id}' 
            data-key='{$cart_item_key}'>
            Swap with <strong>{$alt_post->post_title}</strong> ($alt_price - Save $savings)
        </button>";
    }
    echo '</div>';
}, 10, 2);

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2. JS: Handle Product Swaps via AJAX

Enqueue this JavaScript and make sure it runs only on the cart page:

add_action('wp_enqueue_scripts', function() {
    if (is_cart()) {
        wp_enqueue_script('downsell-swap', plugin_dir_url(__FILE__) . 'swap.js', ['jquery'], null, true);
        wp_localize_script('downsell-swap', 'DownsellData', [
            'ajax_url' => admin_url('admin-ajax.php'),
            'nonce' => wp_create_nonce('swap_nonce'),
        ]);
    }
});

Then create swap.js:

jQuery(document).ready(function($) {
    $('.swap-product-btn').on('click', function(e) {
        e.preventDefault();

        const btn = $(this);
        const original_id = btn.data('original');
        const alt_id = btn.data('alt');
        const cart_item_key = btn.data('key');

        btn.prop('disabled', true).text('Swapping...');

        $.post(DownsellData.ajax_url, {
            action: 'swap_cart_item',
            nonce: DownsellData.nonce,
            cart_item_key,
            original_id,
            alt_id,
        }, function(response) {
            if (response.success) {
                location.reload(); // Refresh cart
            } else {
                alert('Swap failed: ' + response.data);
                btn.prop('disabled', false).text('Try again');
            }
        });
    });
});

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3. PHP: AJAX Handler for Product Swap

Add this in your plugin or functions file:

add_action('wp_ajax_swap_cart_item', 'handle_cart_item_swap');
add_action('wp_ajax_nopriv_swap_cart_item', 'handle_cart_item_swap');

function handle_cart_item_swap() {
    check_ajax_referer('swap_nonce', 'nonce');

    $key = sanitize_text_field($_POST['cart_item_key']);
    $original = intval($_POST['original_id']);
    $alt = intval($_POST['alt_id']);

    if (!WC()->cart->remove_cart_item($key)) {
        wp_send_json_error('Could not remove original product');
    }

    $exists = false;

    foreach (WC()->cart->get_cart() as $item_key => $item) {
        if ($item['product_id'] == $alt) {
            WC()->cart->set_quantity($item_key, $item['quantity'] + 1);
            $exists = true;
            break;
        }
    }

    if (!$exists) {
        WC()->cart->add_to_cart($alt);
    }

    wp_send_json_success('Cart updated');
}

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Result: A Dynamic, User-Friendly Downsell Experience

• 🧲 Suggests cheaper products in real-time.
• ⚡ Users swap items without reloading the page.
• 📉 Increases chances of checkout from hesitant buyers.

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Final Thoughts

Smart downselling creates value for both you and your customers. It’s not about selling less—it’s about closing more sales.

With this WooCommerce downsell setup, you give your customers a helpful nudge—at the perfect time.

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