Shoppers now build their cart on Google before they reach your store
Google Universal Cart went live in the US on Oct 15. One cart for products from many stores, across Search and the Gemini app. Here is how it works, and a four-point check for your product data.
On Oct 15, Google said its Universal Cart is now available to US users across Search and the Gemini app. Google first previewed it at I/O in May. A shopper can save items from several stores into one cart, and come back later to pick.
What launched
Google describes the cart as a hub for shopping on Google. The shopper saves products wherever she is shopping on Google. Google’s own example: a handbag from Steve Madden saved in AI Mode, then a sweater from Quince and lipgloss from Ulta Beauty saved in the Gemini app. They are all in the cart when she comes back.
TechCrunch adds that the cart can send notifications when a saved item’s price drops or an out-of-stock item returns, and that checkout is tied to UCP, the Universal Commerce Protocol, an open standard Google introduced earlier this year.
Four things the cart does
Google lists four. One, it saves products from multiple retailers. Two, it keeps tabs on price and inventory changes, built on the more than 60 billion continually refreshed listings in Google’s Shopping Graph. Three, it uses Google Wallet to understand card perks and shows relevant promo codes. Four, checkout.
On checkout, Google says shoppers can pay with Google Pay in a few taps with many stores right in the cart, or transfer their items to the merchant’s cart and finish on the merchant’s site. It names Nike, Sephora, Target, Ulta Beauty, Walmart, Wayfair and many Shopify merchants as places to try this. The merchant remains the seller of record and handles confirmations and customer support.
Your store sees the cart last
Google’s Cart API guide for developers describes how the handoff works. Google accumulates the items on its side as the shopper adds them. It does not call the merchant for each one. A single request, to create a cart, is sent only when the shopper clicks the button to transfer the cart to your store. That request carries every line item at once, and your system replies with a link that continues the cart on your site.
So the comparison, the saving and the waiting all happen before your system hears anything. If the shopper pays with Google Pay in the cart, the guide does not describe a visit to your site at all. The guide is technical and covers the handoff, not how often each path is used.
Why more AI traffic raises the stakes
This lands as more shoppers arrive through AI. Adobe Analytics data reported by Digital Commerce 360 says AI-referral traffic to US retail sites rose 62% year over year in July 2026. Adobe also found AI referrals brought 53% more revenue per visit and converted 60% higher than other traffic. Adobe sells analytics software, and this is its own data on its customers’ sites.
The same article says Adobe found 39% of the retailer homepages it analyzed are not machine-readable. That is Adobe’s cohort, not a measure of any one store.
A four-point check before the holidays
Google’s page does not say what data decides who wins when two stores sit side by side in a cart. These four checks are our advice. They are what a shopper would compare, and the first place an alert would be wrong.
- Price and compare-at price match what you actually sell today. The cart watches for drops.
- Stock and sizes are current. The cart watches for items coming back.
- Shipping and returns copy is the same on every page.
- Promotions you want shown are live in Merchant Center. The cart shows relevant promo codes.
A shared cart makes comparison easy. Wrong data makes you lose that comparison quietly.
How Shopthru.ai helps
Shopthru.ai is an AI agents team for consumer brands. It asks ChatGPT, Gemini, Google AI, Perplexity and Copilot what your shoppers ask, finds where AI gets your products, prices or policies wrong, and drafts each fix into an approval inbox. It ships only on your yes, then checks again. Instagram and Amazon are next.