2026-09-02 Note: This article records a product assessment from October 2023. Discount Kit’s plans, features, beta labels, and availability may have changed since publication.
Discounts on Shopify have always been slightly awkward. Easy to use and understand, but not flexible enough to do anything out of the ordinary. The launch of Shopify Functions for Discounts earlier this year promised to solve this once and for all. However, using it means creating a custom app, which is way more involved from my beloved, but deprecated Shopify Scripts. And in either case, Shopify Plus was needed, which is not accessible to everyone.
A few weeks ago, I found out about a public app that uses Shopify Functions for Discounts under the hood, and opens up the whole logic for complex discounts to everyone. Being a public app, it can also be used on all Shopify plans! Enter Discount Kit.
In addition to using native discounting features and letting merchants create volume, gift-with-purchase, and order-goal discounts (added automatically to the cart with no input from the client!), it exposes Shopify Functions through its “Custom Discount” feature. I was lucky enough to be included in the beta for it, and from my tests, it works beautifully!
One discount that had been impossible or extremely convoluted for the customer was applying different discounts on different products within the same cart. It was possible after discount stacking was introduced the previous year, but it was hell for customers, who had to enter different codes one after the other at checkout.
Custom discounts let you do that in 2 minutes. Bonus points: it’s done within the native discounts interface, so you don’t have to juggle between native discounts and app discounts! Here’s what it looks like:
Now, the “All” application strategy is still in beta, and has some quirks, like having only the first message show up. I understand this is a limitation from the Shopify Discounts API at the moment, so it should be fixed soon enough. The actual discount allocation works fine, which is what’s important!
With this, I can say with confidence that discounts are no longer a weak point on Shopify. This app has all the functions from the Discount Functions API within a slick user interface, and their support is great. It can also be used on all Shopify plans, which is great!
A small aside for developers (non-devs can skip this), they also include a client-side JS API to build things on top of. It’s still an early build, and it doesn’t support Custom Discounts (yet), but it gives access to all active discounts within an event named ‘discount_kit:engine_result’. Here’s what it looks like:
With that event data, you can build anything you need related to showing discounts within the theme, either showing available discounts on the cart, volume discount tables on the product page, or anything else, really. The data is there!
Go check it out on the free trial! I bet you’ll keep it after it ends.