How can I locate and remove unused Javascript for faster online store speed?

Technical Q&A

Topic summary

Goal: Speed up an online store by removing unused JavaScript flagged by Google PageSpeed Insights.

Context: The store owner already deleted unneeded products/files, compressed images, removed old apps, and optimized SEO. They searched theme.liquid, header.liquid, and product-template.liquid but couldn’t find the scripts or remnants of old apps.

Key advice:

  • Reducing unused JavaScript is difficult without developer expertise. One suggestion is to consider web workers (running scripts in the background) to offload heavy tasks.
  • Many scripts are injected by Shopify apps and may not appear directly in theme files, making manual removal difficult.
  • External guides were shared for steps to audit and remove unused JavaScript and Shopify-specific cleanup.

Outcomes/decisions: No concrete code locations or specific removals were identified. Offers for direct support were made.

Status: Unresolved. Next steps implied include reviewing the linked resources, investigating app-injected scripts, and potentially seeking developer assistance to isolate and reduce unused JavaScript.

Summarized with AI on February 2. AI used: gpt-5.
1

Hi, I’m trying to get my online store faster. I’ve been already deleting products/pictures/files that are no longer needed. I’ve also compressed images and cleaned up old apps and optimised SEO. However, when testing the speed on PageSpeedInsight, it suggests to reduce unused Javascrip. I’ve checked for this on theme.liquid, header.liquid, and product-template.liquid. but couldn’t find the codes that need to be removed.

Also, I couldn’t find the old app codes to remove them manually.

Where are these annoying codes exactly?

Any help would be much appreciated.

1 Like
2

Hello,

We are OneExperts from OneCommerce - an eCommerce solution platform.

Pagespeed report show that you need to:

  • Reduce unused JavaScript
    It was hard to fix this issues if you are not a developer, some of my suggestions for you are that you learn about web workers to fix these problems, you can refer to the documentation on youtube.

Hope this can help you solve the problem.

If you need any further support, hit us up at julia@onecommerce.io for replies within minutes

3

Hello @Lulakarpo APP scripts are running from apps you cant handle them or check if any of them inside the theme files. There are many resources in google you can follow them

https://weeklyhow.com/how-to-clear-unused-codes-in-shopify/

https://sitechecker.pro/site-audit-issues/remove-unused-javascript/

If you need more help feel free to contact thanks.