Best Squarespace Slide-Out Cart Plugin: Full Review and Setup Guide
If your Squarespace store still uses the default cart page — where clicking the cart icon navigates the customer away from what they were browsing — you're losing sales every day. Not because customers don't want to buy. Because the friction of leaving the page interrupts the buying momentum you've worked hard to build.
A slide-out cart plugin fixes this. Here's a full review and setup guide for the best Squarespace slide-out cart plugin available in 2025.
What Is a Slide-Out Cart?
A slide-out cart (also called a cart drawer or mini cart) is a panel that slides in from the side of the screen when a customer adds something to their cart or clicks the cart icon. Instead of navigating to a separate cart page, the customer sees their cart contents in a panel while staying on the current page.
They can review items, adjust quantities, see the order total — and proceed to checkout — all without leaving the product page they were browsing. The buying momentum stays intact.
Why It Matters for Revenue
Two things happen when you replace the default Squarespace cart with a slide-out drawer:
Fewer interruptions. Every page navigation is a potential exit point. A customer who's taken to the cart page has to consciously choose to come back and keep shopping. The slide-out drawer keeps them where they are.
More upsell opportunities. The drawer is a natural place to show offer suggestions. A customer who's just added something to their cart is at peak purchase intent. Showing an offer inside the drawer — while they're reviewing what they've added — converts significantly better than showing the same offer on a separate page.
Does Squarespace Have a Slide-Out Cart Natively?
No. Squarespace 7.1 uses a traditional cart page by default. There's no native slide-out drawer. To add one, you need a plugin.
The Best Squarespace Slide-Out Cart Plugin: UpsellGrow
UpsellGrow includes a slide-out cart as part of its full upsell system. The drawer replaces the default Squarespace cart behavior — clicking the cart icon or adding a product opens the panel instead of navigating to the cart page.
What the Drawer Includes
- Cart items with product names, images, variants, and quantities
- Quantity adjustment and item removal
- Order subtotal
- Checkout button
- Upsell offer positions inside the drawer
Three Offer Positions Inside the Drawer
UpsellGrow supports three offer positions in the slide-out cart:
- Inside drawer — above checkout: Appears between the cart items and the checkout button. Catches the customer right before they proceed to payment.
- Inside drawer — below items: Appears below the cart items, above the subtotal. Appears as the customer reviews what they've added.
- Popup on checkout click: Fires a popup when the customer clicks the Checkout button. High-intent, last-chance moment.
Offer Types That Work in the Drawer
All three UpsellGrow offer types — cross-sell, bundle, and FBT — work inside the slide-out cart. Bundle offers perform particularly well here: the customer can see their current cart and evaluate whether adding more products at a discount makes sense for them.
Cart Trigger Behaviour
UpsellGrow lets you configure which product in the cart triggers the offer: the last product added, the highest-value product in the cart, or the highest-priority offer regardless of cart contents. This ensures the most relevant offer fires for each customer's specific cart state.
Setup
Install UpsellGrow on your Squarespace 7.1 store. The slide-out cart is enabled by default. To add offers inside the drawer, create a new offer, select "Slide-out Cart" as the location, configure the offer, and choose one of the three drawer positions. Publish. Done.
The Full Picture
The slide-out cart is one part of UpsellGrow's five-location system. Offers also work on the product page (6 positions), the cart page (5 positions), the order confirmation (4 positions), and the order status page (4 positions). If you're going to add a slide-out cart plugin, it makes sense to use one that handles the full upsell funnel rather than just the drawer.
Ready to Start Earning More From Every Order?
UpsellGrow adds upsells, cross-sells, bundles, and frequently bought together offers to your Squarespace store — across 5 pages and 19 positions. No coding. Setup takes minutes.