How to Add Upsell Offers on Shopify Checkout Page
The checkout page is the last place a customer looks before completing a purchase, making it the highest-converting real estate in your store. Adding upsell offers here—like a discounted accessory or a premium version of the item in their cart—can dramatically increase your Average Order Value (AOV). Here is exactly how to add upsell offers on the Shopify checkout page, using both app-based and code-based methods.
Why Add Upsell Offers at Checkout?
Unlike product pages or pop-ups, checkout offers target buyers who have already committed to spending money. They have their credit card out and are in a buying mindset. At this stage, the friction to add another item is lower than the friction to start a new product search.
The primary benefit is simple: increased revenue per transaction without spending more on ads. You are monetizing existing traffic. Additionally, offering a relevant, time-sensitive bundle can reduce the likelihood of cart abandonment because the customer feels they are getting a "deal" on their final total.
Method 1: Using Shopify Apps for Checkout Upsells
For most merchants, the fastest and safest route is a third-party app. Since Shopify restricts direct code edits on the checkout page (unless you are on Shopify Plus), apps use the official checkout extension points to place offers.
Recommended workflow:
- Choose a post-purchase or pre-purchase app. Popular options include ReConvert, Zipify OneClickUpsell, or AfterSell. These are specifically designed for one-click offers.
- Install the app from the Shopify App Store. Look for apps with a high rating (4.5+ stars) and a track record of supporting the latest "Shopify Functions" checkout requirements.
- Create your offer. In the app dashboard, select the trigger (e.g., cart total above $50) and the product you want to offer.
- Set the offer logic. Most apps let you show the offer after the "Pay Now" button is clicked but before the payment is fully processed (post-purchase), or directly on the checkout summary page (pre-purchase).
- Customize the copy. Use urgency ("Add this for 30% off before you finish") and show a product image thumbnail.
Pros and Cons of Apps
| Pros | Cons |
|---|---|
| No coding required – Set up in minutes. | Monthly subscription fees – Check current pricing for your sales volume. |
| A/B testing built-in – Most apps provide analytics to compare offer performance. | Third-party dependency – If the app fails, your checkout might be affected (though rare). |
| Works on all Shopify plans – You do not need Shopify Plus for basic post-purchase upsells via apps. | Limited customization – You are bound by the app's design templates. |
Method 2: Custom Code with Shopify Functions
If you are on a Shopify plan that supports Shopify Functions (Advanced or Plus) and have development resources, you can build a custom upsell. This method gives you total control over logic and design but requires more technical skill.
The modern approach uses "Shopify Functions" for discounts and "UI Extensions" to render the offer.
Here is the high-level process:
- Create a Shopify Function app using the Shopify CLI. This handles the backend logic.
- Define the discount logic. You will write a function that checks the cart contents. For example, if the cart contains a specific "Base Product" ID, the function automatically applies a 15% discount to the "Upsell Product" ID when that upsell product is added.
- Build the UI Extension. This is a separate component that tells the checkout where to render your offer block (e.g., below the line items). You will use Liquid or React to display the product and an "Add" button.
- Handle the "Add to Cart" action. The UI extension calls a mutation to add the item to the draft order, then triggers the function to recalculate the total.
Important note: Shopify is deprecating the old ScriptTag and Checkout.liquid methods for checkout. Do not use those old tutorials. Focus solely on Shopify Functions and Checkout UI Extensions for future-proofing.
Best Practices for Checkout Upsells
To avoid annoying customers and maximize conversion, follow these rules:
- Offer only 1–2 items. Do not turn your checkout into a shopping spree. A single, highly relevant offer converts best.
- Make it complementary. If they are buying a camera, offer a memory card or a spare battery. Never offer a competing camera.
- Use a clear discount. A specific dollar amount off (e.g., "Add for $10 off") often outperforms a percentage (e.g., "Add for 20% off") for low-priced items.
- Keep it visual. Show a high-quality image and the discounted price immediately. Do not make the customer click to see the product page.
- Test post-purchase first. If you are new, try a post-purchase offer (after payment). It has zero risk of decreasing checkout conversion because the main sale is already done.
Measuring the Success of Your Upsell Strategy
You cannot improve what you do not measure. Track these metrics in your Shopify Analytics and your upsell app's dashboard:
- Upsell Acceptance Rate: The number of customers who clicked "Yes" divided by the number who saw the offer. A good baseline is 10–15% for pre-purchase and 20–30% for post-purchase.
- Average Order Value (AOV): Compare your AOV for the 30 days before the upsell went live to the 30 days after.
- Revenue per Visitor (RPV): This is more important than raw conversion rate. If your checkout conversion drops by 2% but your AOV jumps by 15%, your RPV likely went up.
- Refund Rate: Watch for an increase in returns. If customers are returning the upsell item, the product fit is wrong.
Common Mistakes to Avoid
- Offering irrelevant products. A dog toy upsell on a cat food purchase looks lazy and fails.
- Hiding the shipping cost. If the upsell pushes the cart over a free shipping threshold, mention that explicitly. "Add this to unlock free shipping" is a powerful trigger.
- Using slow images. A heavy image on the checkout page can delay the loading of the payment form. Compress your images to under 100KB.
- Forgetting mobile. Over 80% of e-commerce traffic is mobile. Ensure the upsell button is big enough to tap with a thumb and that the text is not cut off.
Final Thoughts: Start Increasing Your Average Order Value
Adding upsell offers on the Shopify checkout page is one of the most effective ways to increase profitability without acquiring new customers. Start with a simple app-based post-purchase offer to test the waters, then refine your product selection and discount strategy based on your data. Once you see consistent results, you can consider a custom build for deeper integration. The key is to act now—every order that goes through your checkout today is a missed opportunity to add more revenue.
Frequently Asked Questions
Can I add upsells to the checkout page on the basic Shopify plan? Yes, you can use third-party apps like ReConvert or Zipify on the Basic plan. These apps use Shopify's approved checkout extensibility, which is available to all plan tiers, though some advanced features may require a higher plan.
Will an upsell slow down my checkout process? Only if you use poorly optimized code or heavy images. Reputable apps are built to load asynchronously, meaning the "Pay Now" button works immediately. The upsell appears after the payment is processed, so it does not delay the main sale.
What is the difference between a pre-purchase and post-purchase upsell? A pre-purchase upsell appears on the checkout summary page before the customer enters their payment details. A post-purchase upsell appears after the customer clicks "Pay Now" and the payment is authorized, but before the thank-you page. Post-purchase offers have zero risk of decreasing your checkout conversion rate.