Shopify Scripts replaced by Shopify Functions, a Top Tool for Boosting Your Ecommerce Store’s Performance



At its core, e-commerce is all about the customer.

It’s about understanding their preferences and needs, and delivering an exceptional shopping experience.

That’s why Shopify has been continuously innovating to provide merchants with the tools they need to create personalized and seamless shopping journeys for their customers.

In today’s blog post, we’ll discuss the next evolution in Shopify’s customization capabilities: the transition from Shopify Scripts to Shopify Functions. Read on!

Why are Shopify Scripts being replaced by Shopify Functions?

In response to the evolving demands of the e-commerce industry, Shopify has introduced Shopify Functions as a replacement for Shopify Scripts. This transition signifies a commitment to providing merchants with enhanced flexibility and simplicity in customizing their online stores.

With Functions, you can easily personalize your customers’ shopping journeys and optimize your online stores without complex code modifications.

This transition opens up new possibilities, simplifying the customization process and empowering merchants to deliver exceptional shopping experiences effortlessly.

What are Shopify Functions?

So, what exactly are Shopify Functions and how do they work?

Similar to their predecessor, Functions are small snippets of code that extend the functionality of your Shopify store. They can be customized to suit your specific business needs, allowing you to streamline checkout processes, implement smart pricing strategies, and provide targeted product recommendations.

However, Functions take this customization capability to the next level by offering a more user-friendly approach.

With Shopify Functions, you no longer need to worry about modifying code or dealing with technical complexities. Instead, Functions are installed as apps and can be configured directly within the Shopify Admin interface.

This means that even non-technical users can leverage the power of Functions to enhance their store’s performance and customer experience.

A print screen of a shopify functions' window


How do Shopify Functions work?

With Functions, you can seamlessly extend and customize the functionality of your Shopify store to cater to your unique business needs.

But what does this process look like in practice?

To begin, you’ll need to install an app that supports Shopify Functions. This app acts as the gateway to unlocking the full potential of Functions.

Once installed, you’ll gain access to a wide array of customizable options that can be configured directly within your Shopify Admin interface.

The beauty of Shopify Functions lies in their user-friendly nature. You don’t need to be a coding expert or hire a development team to leverage the power of Functions. With just a few clicks, you can effortlessly customize key aspects of your store, such as discounts, shipping methods, and payment options.

But how exactly do you configure these customizations?

Well, it’s as simple as navigating through the user-friendly interface of the Shopify Admin. Just like you would adjust the built-in features of your store, you can now fine-tune the behavior and functionality of Functions. It’s a seamless integration that empowers you to create a truly tailored shopping experience for your customers.

Lifecycle of a Shopify Function

Let’s now take a closer look at the lifecycle of a Shopify Function, which demonstrates how these powerful tools operate seamlessly within the Shopify ecosystem. The following diagram provides an overview of the process:

A graph showing the lifecycle of shopify functions


App developers play a crucial role in creating and deploying apps that contain various functions. These functions act as the building blocks for customizations and enhancements tailored to specific merchant needs.

Merchants, like yourself, have the opportunity to install these apps directly on your Shopify store. Once installed, you can easily configure the functions to align with your desired settings and preferences. This configuration is done through an API call, ensuring a smooth integration between the app and your store.

As customers interact with your Shopify store, the magic happens behind the scenes. Shopify executes the function based on the predefined configuration, seamlessly weaving it into the customer journey.

To provide an example, imagine an app developer creating an app with a function that introduces a unique discount type. As a merchant, you can then install this app on your Shopify store and effortlessly create a new discount utilizing the discount type provided by the app. When a customer adds a product to their cart, Shopify springs into action, executing the function to calculate the applicable discount.

New Shopify Functions APIs

Here are the new Shopify Functions APIs that provide developers with powerful tools to enhance commerce experiences:

Cart Transform API (Developer preview)

Gives merchants the power to create unique bundle offerings. Combines specific products into a bundle with a new bundle price at checkout. Expands bundle products into individual components for backend tasks like inventory management and fulfillment.

Cart and Checkout Validation API (Developer preview)

Ensures compliance with specific purchase rules. Controls minimum/maximum quantities, shipping address restrictions, and incompatible item combinations. Enables tokengated commerce experiences for exclusive collections or discounts.

Order Routing API (Developer preview)

Optimizes order fulfillment and shipping. Defines rules for warehouse allocation, proximity-based shipping, split-fulfillment prevention, and inventory balancing. Customizes routing logic based on the merchant’s needs.

Delivery and Payment Customization APIs

Tailors delivery and payment options to meet unique merchant requirements. Customizes delivery options based on location or buyer preferences. Hides or prioritizes payment methods based on order value.

Two men sitting at one desk and looking at some code, working with two laptops and one big screen

Benefits of Shopify Functions

So, what are the benefits of embracing Shopify Functions for your e-commerce store? Let’s explore the advantages that this powerful customization tool brings to the table:

Simplified customization

With Shopify Functions, you can customize and extend the functionality of your store with ease, thanks to a user-friendly interface that requires no technical expertise. The simplified customization process empowers you to make impactful changes to your store’s behavior, ensuring a tailored shopping experience for your customers.

Enhanced performance

With Shopify Functions, you can rest assured that your customizations won’t slow down your store's performance. These functions are designed to execute in under 5ms, guaranteeing optimal speed and responsiveness. Whether it’s a regular sales day or a massive flash event, your store will be equipped to handle it all seamlessly.


Shopify Functions are built to scale effortlessly alongside your store. Whether you’re managing a small online boutique or a global e-commerce empire, Functions adapt to meet the demands of your business. You can customize with confidence, knowing that your store will perform flawlessly, no matter the size of your audience.

Tailored shopping experiences

With Shopify Functions, you have the power to create personalized and tailored experiences that resonate with your audience. From customized discounts and shipping methods to specialized checkout processes, Functions allow you to fine-tune every aspect of your customer’s journey, enhancing engagement and boosting conversions.

Accessibility for all

You don’t need to be a coding expert or have an extensive development team to leverage the benefits of Shopify Functions. These powerful customizations are accessible to merchants of all skill levels. With just a few clicks, you can configure and deploy Functions directly within your Shopify Admin interface. It’s a level playing field, allowing you to compete with larger enterprises and create unique experiences for your customers.

Future-proof customizations

With Shopify Functions, you’re always on the cutting edge of innovation. These functions are built to evolve alongside the platform, ensuring compatibility with future updates and enhancements. You can trust that your customizations will remain aligned with the latest advancements, giving you peace of mind and the freedom to focus on growing your business.

A white desk with a laptop on it, two hands on the laptop's keyboard writing some code

Shopify Plus-exclusive features

Shopify has also introduced a range of exclusive features tailored specifically for Shopify Plus brands:

Custom functionality

As a Shopify Plus brand, you have the unique advantage of creating your own custom Functions. This means you have the freedom to build functionality that is tailored precisely to your business needs. Whether it’s a specific discount, shipping method, or payment use case, you can now develop custom Functions that address your unique requirements.

Brand-specific apps

Need a specialized app for your store? With Shopify Plus, you have the exclusive ability to build and distribute your own custom apps. If a specific functionality isn’t available in the Shopify App Store or if you require a niche solution, you can simply develop your own app and distribute it exclusively to your store. This level of control ensures that your brand remains at the forefront of innovation, setting you apart from the competition.

Elevated performance

Shopify Plus brands often experience high volumes of traffic and sales. To accommodate these demands, Shopify Plus-exclusive features are designed to provide enhanced performance and scalability. You can rest assured that your store will remain stable and responsive, even during peak periods or flash sales. This reliability allows you to focus on growing your business without worrying about technical limitations.

Dedicated support

As a valued Shopify Plus merchant, you gain access to a dedicated support team that understands the unique challenges and requirements of high-growth businesses. With priority access to Shopify’s expert support staff, you can resolve issues quickly and efficiently, ensuring minimal disruption to your operations. Whether you have technical queries or need guidance on maximizing the potential of your store, the dedicated support team is there to assist you every step of the way.

Advanced reporting and analytics

Shopify Plus-exclusive features also encompass advanced reporting and analytics capabilities. You can gain deeper insights into your store’s performance, track the effectiveness of your custom Functions, and measure the impact of your marketing efforts. This data-driven approach empowers you to make informed decisions, optimize your strategies, and drive sustainable growth for your business.

A man sitting at his desk with two laptops and one big screen, two keyboards and a lot of notes, working on some code or something similar

Shopify Functions limitations

When working with Shopify Functions, it’s important to be aware of the following limitations:

  • Nondeterminism restriction: Randomizing or clock functionality can’t be used in the functions
  • Size limit: the compiled function mustn’t exceed 256 kB in size
  • Debugging: STDOUT can’t be used for debugging; instead, use STDERR for function output
  • Truncated logs: function logs to STDERR are truncated after 1 kB, which may cause issues with certain Wasm toolchains
  • Instruction limit: the function's logic must execute within a maximum of 11 million instructions and can be tested locally using function-runner.
  • Memory limits: at runtime, the function's linear memory limit is 10 MB, and the stack memory limit is 512 kB.
  • Input size: a function's input cannot exceed 64,000 bytes in size. Refer to input query limitations for more details.
  • Output size: the output of a function cannot exceed 20 kB in size.
  • Deployment limit: An app can deploy a maximum of 50 functions.
  • Network access: Network access is not supported within functions, meaning you cannot send HTTP requests to your app's backend. However, you can utilize metafields on products and customers, or pass data using cart attributes to pre-populate data.

Being mindful of these limitations will ensure that your Shopify Functions operate within the defined boundaries, enabling you to build powerful customizations while staying within the platform's constraints.

Overcome all the limitations by partnering with our Shopify expert

While the limitations of Shopify Functions may initially appear daunting, they can be easily overcome by partnering with an experienced software house just like From Poland With Dev

By joining forces with our team of experts, you can navigate through these challenges effortlessly, saving valuable time, stress, and energy.

Our software house specializes in Shopify development and possesses a deep understanding of the platform's intricacies.

We offer tailored solutions that address your specific needs, ensuring seamless integration and optimal performance. 

With our dedicated support and maintenance services, you can confidently focus on growing your e-commerce business while leaving the complexities of Shopify Functions in our capable hands.

Together, let’s unlock the true potential of Shopify Functions and drive your business towards success!

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