Best FBT apps for Shopify

FBT means frequently bought together: a small set of products, usually on the product page, that a shopper can add in one action. US stores mix that phrase up with two other offers. A quantity break is a cheaper unit price when the shopper buys more of the same SKU. A build-your-own box is a kit the shopper assembles. The best FBT app is the one that matches the offer you can actually fulfill.

Best FBT apps for Shopify, by offer

Oxify Quantity Breaks & BYOB

Oxify Quantity Breaks & BYOB is the app we would install when a US catalog needs more than one bundle type. The listing covers quantity breaks and tiered volume discounts, BOGO, Buy X Get Y, free gifts that add themselves, fixed bundles, mix-and-match, multipacks, and a build-your-own-box builder. Discounts auto-apply at checkout with no code. Analytics and A/B tests are named. It works with cart drawers, and the listing names Oxify Cart, Upcart, and AOV.ai, plus GemPages, PageFly, and EComposer.

The headline says free bundles app. The plan on the page we read is Black Friday 2026 at $1 a month, including unlimited bundle deals. Shopify showed that as about ₹94 on a non-US view, which matches a $1 list price at the same rate as Oxify's other app. Holiday pricing ends. Open the listing in the admin and read the renewal price. The app is Built for Shopify, rated 4.9 from 13 reviews, launched July 30, 2025, and the developer is Oxify App. Languages include English, Spanish, and French, which covers a US brand that also sells to Canada in French.

A US review on the listing, from Snuggle and Hush on August 25, 2026, says the bundle builder had the features they wanted and that support helped them design it. That is one merchant after about four months. It is not a sample of US stores. Thirteen reviews is still a short record next to Code Black Belt's 1,212.

Foxr Bundle Builder

Foxr Bundle Builder is the free app when the offer is a box, not a pair of checkboxes. It launched September 24, 2026, is priced Free, and is rated 5.0 from 4 reviews. Shoppers build the box on a landing page or on the product page. You can set tiered percent-off, amount-off, or a set total, show a progress bar, unlock a bonus gift, and add a step for extras, gift notes, and gift packaging. Rules cover quantity, spend, and which products can sit together. Funnel analytics and A/B testing are on the listing. The language is English. The developer is FOXR APP in the United Kingdom.

The app's data access includes cart transforms, which is Shopify Functions. That is the right mechanism for a bundle price that has to survive checkout, Shop Pay included. Four reviews and a September 2026 launch mean you test the box on a duplicate theme with a real inventory count. A builder that lets someone assemble a sold-out shade is a support ticket.

FBT inside the cart

Oxify Cart Drawer & Upsell lists cart upsell, cross-sell, and FBT bundles on every plan, from $9.99 a month. Use it when the pair should show up as the shopper is about to check out, not only under the product description. Do not also install a second drawer. Foxr's free cart is the alternative if you only need the drawer and you do not need Oxify's post-purchase page. Compare them in the cart drawer guide.

The dedicated frequently-bought-together widget

Frequently Bought Together by Code Black Belt is the app with the review history this category usually demands. On November 9, 2026 it was Built for Shopify, rated 4.9 from 1,212 reviews, with a free plan listed and a $9.99 plan for up to 50 orders a month. That paid plan includes unlimited manual bundles, automatic and global recommendations, a widget on the product and cart pages, and bundle discounts. A Black Friday note on the dollar listing offered $5 off the first payment.

Choose Code Black Belt when the job is an Amazon-style set of checkboxes and you want a vendor that has shipped that widget for years. Choose Oxify Quantity Breaks when you also need volume tiers and a box builder and you will accept 13 reviews to keep the fee at the listed $1. Choose Foxr when the box is the product and the fee has to be zero. Running all three is how a product page grows four widgets and no clear price.

The discount has to survive checkout

A bundle price painted on the product page and a different price in checkout is the failure mode. Oxify's listing says discounts auto-apply at checkout with no code. Foxr's listing sells tiered discounts and uses cart transforms. Code Black Belt's listing includes bundle discounts. Whichever you install, place a test order and compare three numbers: the widget total, the cart total, and the checkout total, with a code applied and without one.

• If two discounts should stack, say so in Shopify's discount combination settings. A bundle plus a sitewide 20% off can zero out a low-margin SKU.
• Write the offer on contribution, not on compare-at price. A 3-for-2 on a 30% margin product gives away the third unit's profit. The worksheet is ROAS vs POAS.
• Cap the box. Foxr's compatibility rules exist so a gift set cannot contain two of the hero and none of the consumable you needed to move.
• Show the saving in dollars. US shoppers respond to $12 off more clearly than to a badge that says bundle.

How to launch one bundle

1. 01Pick one offer from real orders. The pair that already shows up on the same receipt, or the SKU people buy three of.
2. 02Price it so the extra unit still has contribution after the discount, shipping, and a return.
3. 03Install one app. Put the widget in one place: under the add-to-cart button, or in the drawer, not both on day one.
4. 04Test checkout with Shop Pay and with a card. Sales tax calculates in checkout. The merchandise discount should already be in the subtotal.
5. 05Read attach rate and refund rate for 14 days. Keep the bundle that adds contribution. Delete the one that only adds a widget.

Bundles are a merchandising decision that happens to need an app. If the catalog has no natural pair, the app will recommend a best-seller next to an unrelated product and you will discount both. Fix the offer in Shopify development only after you know which two SKUs belong together. The wider slot map is in the upsell app guide.

Which FBT app to install

Install Oxify Quantity Breaks & BYOB when you need volume breaks and a box builder and you have confirmed the $1 plan. Install Foxr Bundle Builder when the shopper should build a box and you want it free, knowing the listing is from September 2026 with 4 reviews. Install Oxify Cart Drawer when the pair belongs in the cart. Install Code Black Belt's Frequently Bought Together when the only job is a checkbox widget and the 1,212 reviews are worth $9.99. One offer, one app, one place on the page.