view_cart

The view_cart event fires when a user views their shopping cart. It gives you a snapshot of the full cart at the moment of viewing — every item, every quantity, the total value. This data powers cart-to-checkout conversion rates and helps you understand the average order value composition before checkout begins.

Unlike add_to_cart (which fires when individual items are added), view_cart reflects the complete current state of the cart when the user explicitly reviews it.

When to fire

Fire view_cart when:

• The cart page or cart drawer renders with cart contents visible
• A cart summary popup/modal opens
• The user navigates back to the cart page

Fire once per cart view, not every time the cart is updated. If the cart updates in real-time (AJAX), you do not need to re-fire unless the user explicitly navigates to the cart view.

Complete dataLayer push

// Always clear previous ecommerce data first
dataLayer.push({ ecommerce: null });

dataLayer.push({
  event: 'view_cart',
  ecommerce: {
    currency: 'USD',
    value: 174.47,    // sum of (price × quantity) for all items
    items: [
      {
        item_id: 'SKU-001-BLK-L',
        item_name: 'Classic Leather Jacket',
        item_brand: 'Heritage Co.',
        item_category: 'Apparel',
        item_category2: 'Outerwear',
        item_variant: 'Black / Large',
        price: 89.99,
        quantity: 1,
        affiliation: 'Online Store'
      },
      {
        item_id: 'SKU-047-WHT-M',
        item_name: 'Cotton Crew T-Shirt',
        item_brand: 'Heritage Co.',
        item_category: 'Apparel',
        item_category2: 'Tops',
        item_variant: 'White / Medium',
        price: 24.99,
        quantity: 2,
        affiliation: 'Online Store'
      },
      {
        item_id: 'SKU-112-TAN-34',
        item_name: 'Woven Leather Belt',
        item_brand: 'Heritage Co.',
        item_category: 'Accessories',
        item_category2: 'Belts',
        item_variant: 'Tan / 34',
        price: 34.50,
        quantity: 1,
        affiliation: 'Online Store'
      }
    ]
  }
});

value: 174.47 is calculated as 89.99 × 1 + 24.99 × 2 + 34.50 × 1 = 174.47.

Event schema

Event Schema view_cart

Parameter	Type	Required	Description
event	string	Required	Must be "view_cart"
ecommerce.currency	string	Required	ISO 4217 currency code. All items must be in the same currency.
ecommerce.value	number	Required	Total cart value — sum of (price × quantity) for all items.
ecommerce.items[]	Array<Item>	Required	All items currently in the cart.
items[].item_id	string	Required	SKU or variant-level product identifier.
items[].item_name	string	Required	Product name.
items[].item_brand	string	Optional	Brand or manufacturer.
items[].item_category	string	Optional	Primary product category.
items[].item_variant	string	Optional	Selected variant.
items[].price	number	Optional	Unit price. Not the line total.
items[].quantity	number	Optional	Quantity in cart.

Calculating cart value

The value parameter should be the sum of all line totals: Σ(price × quantity) for every item in the cart. This is the pre-tax, pre-shipping cart subtotal.

function calculateCartValue(items) {
  return items.reduce((total, item) => {
    return total + (item.price * item.quantity);
  }, 0);
}

// Use with parseFloat to avoid floating-point precision issues
const cartValue = parseFloat(calculateCartValue(cartItems).toFixed(2));

GTM configuration

1. Create a Custom Event trigger. Event name: view_cart. Name it CE - view_cart.

2. Create Data Layer Variables for ecommerce.currency, ecommerce.value, and ecommerce.items.

3. Create the GA4 Event tag. Event name: view_cart. Enable Send Ecommerce data. Add currency and value as explicit event parameters.

4. Test in Preview mode. Navigate to your cart page with items. Verify all items appear in the items array, value equals the correct total, and item-level prices and quantities are correct.

Common mistakes

Omitting items that are out of stock in the cart. Even out-of-stock cart items should be included — the user is seeing them and they’re part of the cart state. Their presence might explain why checkout conversion is lower.

Calculating value as unit price instead of cart total. value must reflect the full cart, not just one item’s price.

Multi-currency carts. If items in the cart have different currencies (rare but possible in marketplaces), standardize to the display currency before pushing.

add_to_cart Individual item additions — the events that built this cart.

begin_checkout The next step — user initiates checkout from the cart.

remove_from_cart Tracking cart removals and quantity reductions.