Shopify Meta Pixel Generator

// Meta Pixel custom pixel for Shopify (Web Pixels API).
// Paste into Settings > Customer events > Add custom pixel, save, then click Connect.
const PIXEL_ID = '1234567890123456';

// Meta's standard base code, adapted to run inside Shopify's pixel sandbox.
!function(f,b,e,v,n,t,tag){if(f.fbq)return;n=f.fbq=function(){n.callMethod?n.callMethod.apply(n,arguments):n.queue.push(arguments)};
if(!f._fbq)f._fbq=n;n.push=n;n.loaded=!0;n.version='2.0';n.queue=[];t=b.createElement(e);t.async=!0;t.src=v;
tag=b.getElementsByTagName(e)[0];tag.parentNode.insertBefore(t,tag)}(window,document,'script','https://connect.facebook.net/en_US/fbevents.js');
fbq('init', PIXEL_ID);
fbq('track', 'PageView');

const plainId = (id) => (id == null ? undefined : String(id).split('/').pop());
const money = (m) => (m && m.amount != null ? Number(m.amount) : 0);
const round = (x) => Math.round(x * 100) / 100;
function itemOf(variant, quantity) {
  variant = variant || {};
  const product = variant.product || {};
  const variantTitle = variant.untranslatedTitle || variant.title;
  return {
    id: variant.sku || plainId(variant.id),
    name: product.untranslatedTitle || product.title || variant.title,
    variant: variantTitle && variantTitle !== 'Default Title' ? variantTitle : undefined,
    price: money(variant.price),
    quantity: quantity || 1,
  };
}
function checkoutItems(checkout) {
  return (checkout.lineItems || []).map((line) => {
    const quantity = line.quantity || 1;
    const unit = money(line.variant && line.variant.price);
    const allocated = (line.discountAllocations || []).reduce((sum, d) => sum + money(d.amount), 0);
    const price = round(Math.max(0, unit * quantity - allocated) / quantity);
    return Object.assign(itemOf(line.variant, quantity), { price });
  });
}
const itemsValue = (items) => round(items.reduce((sum, item) => sum + item.price * item.quantity, 0));

/* ---------- Events ---------- */
analytics.subscribe('product_viewed', (event) => {
  const variant = event.data.productVariant;
  const item = itemOf(variant, 1);
  fbq('track', 'ViewContent', { content_ids: [item.id], content_type: 'product', content_name: item.name, value: item.price, currency: variant.price.currencyCode }, { eventID: 'view_' + item.id + '_' + Date.now() });
});

analytics.subscribe('product_added_to_cart', (event) => {
  const line = event.data.cartLine;
  if (!line) return;
  const item = itemOf(line.merchandise, line.quantity);
  fbq('track', 'AddToCart', { content_ids: [item.id], content_type: 'product', value: money(line.cost.totalAmount), currency: line.cost.totalAmount.currencyCode }, { eventID: 'cart_' + item.id + '_' + Date.now() });
});

analytics.subscribe('checkout_started', (event) => {
  const checkout = event.data.checkout;
  const items = checkoutItems(checkout);
  fbq('track', 'InitiateCheckout', { content_ids: items.map((i) => i.id), value: itemsValue(items), currency: checkout.currencyCode, num_items: items.reduce((sum, i) => sum + i.quantity, 0) }, { eventID: checkout.token });
});

analytics.subscribe('checkout_completed', (event) => {
  const checkout = event.data.checkout;
  const order = checkout.order || {};
  const items = checkoutItems(checkout);
  const transactionId = plainId(order.id) || checkout.token;
  fbq('track', 'Purchase', { content_ids: items.map((i) => i.id), content_type: 'product', value: itemsValue(items), currency: checkout.currencyCode, num_items: items.reduce((sum, i) => sum + i.quantity, 0) }, { eventID: transactionId });
});