An upsell is an offer that gets a shopper to spend more than they planned: a bigger size, a premium version, an add-on or an extra item, shown while they are already buying. For an online store, upselling works when the extra offer is the obvious next step for that exact purchase, and it backfires when it slows down a shopper who was ready to pay.
Below we define the term, walk through the four places a store can show an upsell, and cite real A/B tests from the LiftArchive database, including ones where upsells lost.
Upsell meaning: what does upsell mean?
To upsell is to encourage a buyer to purchase a more expensive item, an upgrade or an extra product on top of what they came for. A coffee shop asking "make it a large?" is upselling. So is a store offering a 3-pack instead of a single unit.
Strictly speaking, an upsell moves the shopper to a higher-value version of the same thing, while a cross-sell adds a different, related product. In ecommerce, most people use "upsell" for both, and most upsell apps do both. If you want the precise split, see our guide to upsell vs cross-sell.
The goal is usually higher average order value. But AOV alone is the wrong scorecard. An upsell that adds $5 to every order but costs you some orders can lose money. The tests below are judged on revenue or profit per visitor, which captures both effects.
Types of upsells: pre-purchase, cart, checkout and post-purchase
Where you show the offer changes how shoppers react. Each placement has its own tradeoffs.
Pre-purchase (product page)
These sit on the product page: "frequently bought together" blocks, quantity bundles, or a popup after the add-to-cart click. They reach shoppers while they are still deciding, so a good offer can raise both conversion rate and order size. A bad one adds clutter to the page that does most of your selling. Our upsells element page collects the patterns stores test most.
Cart and cart drawer
Cart upsells show low-cost add-ons next to the items a shopper has already chosen: accessories, gift wrap, a free-shipping top-up. The shopper has committed, so small, cheap offers tend to do well here.
Checkout
Checkout upsells are usually a checkbox or a single "add" button, often called an order bump. On Shopify, apps can only add blocks to the information, shipping and payment steps on Shopify Plus stores, per Shopify's checkout UI extensions docs. Stores on other plans are limited to the cart, the product page and the post-purchase and thank-you pages.
Post-purchase
A post-purchase upsell appears after payment, before the thank-you page, and the shopper can accept with one click without re-entering card details. Because the first order is already placed, it can't cost you that sale. On Shopify, these run through post-purchase checkout extensions, and Shopify's developer guide says apps using them need access approval, and only Plus merchants can install custom apps that use them. Our roundup of post-purchase upsell apps covers the App Store options.
Upsell examples from real tests
These results come from our database of ecommerce A/B tests, credited to the practitioners who ran them.
Upsells vs no upsells
Kasper Dolk ran the cleanest version of the question: a store with no upsells against the same store with upsells, with about 398,600 visitors per arm. Adding upsells lifted revenue per visitor by +1.86%, from $1.46 to $1.49, an estimated +$26,471 a month. Profit per visitor rose +1.80%.
Two details matter. The lift was modest, not the doubling some app marketing implies. And AOV barely moved ($97.75 to $97.88); the gain came mostly from conversion rate going from 1.50% to 1.52%. Kasper's advice is to judge upsells on profit per visitor with significance, not just revenue.
Frequently bought together on the product page
Alex Stoykov worked with a golf grip store where installing a grip also needs tape and solvent, but the page only sold the grip. Adding a one-click "Frequently Bought Together" bundle near Add to Cart raised revenue per visitor by +10.87% and conversion rate by +8.09%. The add-on was something buyers needed anyway, which is the best kind of upsell.
The product you offer matters more than the placement
Dave Diederen kept the placement and popup mechanic the same on a supplement brand's product page and only changed which product was offered. The better-fitting upsell won with +7.80% revenue per visitor, +4.37% conversion rate and +3.28% AOV. Dave's takeaway: the winner felt like an intuitive next step.
Milos saw the same thing in a cart drawer. Swapping a leather strap for a mystery box as the cart upsell produced +15.26% revenue per visitor (+$28,912 a month), even though AOV fell 2.48%. Again, the win showed up in conversion, not order size.
Cart add-ons customers asked for
Oliver Kenyon revisited a losing cart test after survey data showed customers wanted gift wrapping but couldn't find it. A visible gift wrapping upsell inside the cart was worth +$58,860 a month. In a separate test, small arrows on cart upsells plus a delivery window line came in at +$127,867 a month, though that test changed two things at once.
Checkout and post-purchase take rates
Some upsell numbers are take rates rather than A/B results. They tell you how often shoppers accept, not whether the store made more money overall. Kasper Dolk reports that fashion clients saw a 50% take rate on a checkbox upsell in the Shopify Plus checkout. Dave Diederen's one-click complementary post-purchase upsell was accepted by 16.64% of buyers at $16.50 per accepted offer.
Across these tests, the winning offers share three traits: the add-on is something the buyer needs or already wants, it costs far less than the main item, and it takes one click to accept. When an offer fails one of those, start by changing the product before you change the design.
@oliverkenyon
@CROguy_
@DaveDiederen
@kasper_dolk@kasper_dolk
@stoykovallex1When upsells hurt conversion
Upsells are not free. Every offer is something a shopper has to read and dismiss, and some of them cost more sales than they add.
- Popups between the cart and checkout. Oliver Kenyon's team removed a $25 pre-checkout upsell popup, redesigned the slide cart and added trust elements, for +$31,000 a month. Because several changes shipped together, the popup's exact share is unknown, but taking an offer away was part of the winning version.
- "Better" offers that confuse. Milos changed a 2-pack offer to "Buy 2 Get 1 Free" at the same $240 price. Revenue per visitor fell 52.38%, an estimated -$104,679 a month. A more generous-looking upgrade lost badly, which is why bundle and quantity upsells need testing.
- Offers that don't fit the purchase. As Dave Diederen's popup test showed, the wrong product in the same slot leaves money on the table. Random "you may also like" items are the most common version of this.
- Too many offers at once. Stacking a product page bundle, a popup, a cart carousel and a checkout bump asks the shopper to say no four times.
- Measuring only AOV or take rate. A high take rate can hide a drop in conversion rate. Kasper Dolk's test showed upsells moving conversion more than AOV, and Milos's cart test won while AOV went down.
A simple rule: run upsells as an A/B test against no upsell, and decide on revenue or profit per visitor. More results are in our cart upsell tests.
Upsell tools
Most Shopify stores run upsells through an app rather than custom code. Shopify's own Search & Discovery app lets you pick up to 10 complementary products per product for themes that show recommendation blocks, which is a reasonable place to start before paying for an app.
Rebuy is one of the larger dedicated options. According to Rebuy's pricing page, as of November 2026 its build-your-own plan starts at $25 a month, priced by monthly Shopify orders, with packages for cart and merchandising, checkout and post-purchase, search, and flows with A/B testing. It offers a 14-day free trial, and a larger Platform One suite is priced through sales.
Rebuy suits growing Shopify stores that want a smart cart, bundles and post-purchase offers from one vendor. It is not for stores outside Shopify, and it may be more than a small catalog needs: because pricing scales with orders and each package is priced separately, costs rise as you add features and volume. Its checkout blocks also run into the same Shopify Plus limits described above.
For side-by-side options, prices and downsides, see our Shopify upsell apps roundup. Whatever tool you pick, test the offer itself: the tests above show that which product you offer matters more than which app shows it.