Reduce Unused JavaScript & Increase Your Page Speed Score

Reduce Unused JavaScript & Increase Your Page Speed Score | Shopify Speed Optimization

In the fast-paced world of online retail, every second counts. Shopify store owners know the importance of a quick-loading website for a seamless user experience. One common speed test error that can plague Shopify stores is the issue of "Unused JavaScript." In this article I'll dive into the causes of this error and explore practical steps to optimize your store's performance.

Understanding the Issue:

The Unused JavaScript error often surfaces during speed tests, causing concern for Shopify store owners. But why does it occur in the first place? The error is closely examined in Google's speed test, which recommends checking the coverage tab in the developer’s area. However, the suggested method of going line by line to identify unused portions can be overly simplistic, especially for app scripts hosted on external servers.

Uninstalling Apps: The Culprit?

One common cause of Unused JavaScript errors is residual code left behind after uninstalling an app. When Shopify apps are uninstalled, they may leave dependencies directly embedded in theme files. To resolve this, store owners should thoroughly inspect their theme.liquid file, searching for script tags related to uninstalled apps, and remove them to clean up the codebase.

Strategically Loading App Scripts:

Even after cleaning up leftover scripts, the Unused JavaScript error might persist. This could be due to the nature of how JavaScript is loaded during a speed test. Google marks certain JavaScript as unused if it's not needed precisely when the test occurs. To address this, it's crucial to strategically load app scripts. Apps that don't require immediate display can be configured for lazy loading using the "defer" or "async" attributes in the theme.liquid file.

Manually Handling Automatic Injections:

If a script is injected automatically and can't be found in theme.liquid, it's time to stop the automatic injection and take control manually. By editing the code in the theme.liquid file and using liquid logic, you can capture the content_for header tag and modify it to exclude the unwanted script. This ensures the app stops working on the front end until triggered by user interaction.

You can find the whole solution and guidance HERE.

Watch the video tutorial here 👇

Conclusion:

Reducing Unused JavaScript errors is crucial for optimizing your Shopify store's speed. Implementing these three strategies—cleaning up residual code, strategically loading app scripts, and handling Shopify-injected scripts—can significantly improve your store's performance. Remember to thoroughly test your store's functionality on a copy theme before making changes to ensure a seamless experience for your customers.

Need Expert Assistance?

If you encounter challenges in identifying and fixing Unused JavaScript errors or other speed issues, consider seeking professional support. Visit Shopioso.com for Shopify support services, and reach out for personalized assistance.

You can find the whole solution and guidance HERE.