On August 28th, 2025 all customized shopping experiences that Shopify Plus brands have built for the add to cart and checkout process using Scripts - such as delivery, payments, and discounts - will be removed from stores and no longer work.
Shopify is urging Shopify Plus brands with existing Scripts to migrate them to Shopify Functions before this date.
Here’s what you need to know ahead of the deadline:
What are Shopify Functions?
According to the Gadget developer blog, “Shopify Functions are small pieces of code which take input, process it, and write output that Shopify uses to customize a very specific part of the buyer experience.”
Here’s a simple outline of how they work, courtesy of Shopify:
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App developers create and deploy apps that contain Functions.
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Merchants install the app on their Shopify store and configure the Function. An API call is made with the Function configuration.
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Customers interact with a Shopify store and Shopify executes the Function.
Why is Shopify switching from Scripts to Functions?
Because Shopify Functions work within Shopify’s backend logic, they are built to handle high volumes of purchases, making them perfect for special events like flash sales and holiday weekends.
Over BFCM 2024 we had a client with large carts reach the CPU limit because the scripts were too heavy/had too many lines. We had to help them troubleshoot, but this wouldn’t have been an issue with Functions.
Another benefit of Functions is that merchants don't need to use code to create store customizations like bulk discounts and free gift with purchase.
Instead, the Functions are installed in the store as part of an app created by 3rd-party developers.
Developers in the Shopify ecosystem have created publicly available apps built on Shopify Functions for common checkout customizations - in fact, there are 28 apps available just for discounts!
If you aren’t able to find an existing app that meets your customization needs, you have the option of creating your own app.
One final advantage of Shopify Functions is that the app can be written using any programming language that can compile to WebAssembly, and is configured directly in the admin dashboard.
Here’s a roundup of additional resources on the topic:
Shopify Manual
Shopify Functions Guide
Functions roadmap
3-Minute Video Tutorial
How long will it take me to migrate from Scripts to Functions?
The amount of time it takes will vary widely from brand to brand.
For example, we have two high-end apparel clients with completely different use cases:
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One has been using Scripts to create basic discounts like “buy X, get Y.” Shopify now offers this natively, so it won’t take much effort to transition to Functions.
- The other has a lot of custom checkout logic built on Scripts, so we’ll have to create specific Functions just for them.
The good news is that Shopify recently launched a new customizations report for Shopify Scripts that recommends Shopify Functions replacements to their existing payment, shipping, and discount customizations.
Merchants can easily export and share the report with agencies, eliminating the need to sift through code to assess their customizations and ultimately accelerate their migration.
I don’t know how to manage the Scripts to Functions migration. Can Coldsmoke help?
Absolutely. Here are the steps we take to help Shopify Plus brands handle the transition:
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Discovery: We assess the situation to see if it’s an easy fix or a more complex project
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Strategy: We come up with a development plan (if you aren’t able to find an existing Functions app that meets your needs, our dev team can create it for you)
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Execution: We facilitate a smooth, painless transition to Functions well ahead of the deadline
👉 If you’d like our assistance in migrating to Functions, please reach out via our contact form.
Our dev team would be happy to guide you through the process.
