How to Remove Unused Shopify App Code

Why Apps Leave Code Behind

When you install a Shopify app, it often modifies your theme to add its functionality. This might include injecting scripts into theme.liquid, adding snippet files, or embedding liquid code in specific templates.

When you uninstall the app, Shopify removes the app itself but frequently leaves the theme modifications in place. This happens because Shopify cannot always determine which code belongs to which app, especially if the theme has been modified by multiple apps over time.

Performance Impact

Leftover app code can significantly impact your store's performance. Even if the main app functionality is gone, the code still loads and executes on every page view.

Identifying Leftover Code

Before removing anything, you need to find the residual code. Here are the methods to identify it.

Using Browser DevTools

1. 1.Open your store in Chrome and press F12 to open DevTools
2. 2.Go to the Network tab and reload the page
3. 3.Filter by JS and CSS to see all loaded scripts and styles
4. 4.Look for requests to external domains you do not recognise
5. 5.Check for failed requests (shown in red) which indicate dead app scripts

Using Page Source

1. 1.Right-click on your page and select "View Page Source"
2. 2.Search (Ctrl+F) for common app indicators: "app-embed", "cdn.shopify", app names
3. 3.Note any script or link tags that reference apps you have uninstalled

Checking Theme.liquid

The theme.liquid file is the most common location for app code injection. Apps typically add their scripts just before the closing head or body tags.

1. 1
   Open Theme Code

   Go to Online Store > Themes > Actions > Edit code. Open the theme.liquid file from the Layout folder.

2. 2
   Search for App References

   Use Ctrl+F to search for app names, "snippet", "include", and external script sources. Look for comments like "Start App Name" or "Added by App Name".

3. 3
   Check Near Head and Body Tags

   Scroll to just before </head> and </body>. These are common injection points for app scripts.

<!-- Start ReviewApp -->
{% include 'review-app-script' %}
<script src="https://cdn.reviewapp.com/widget.js"></script>
<!-- End ReviewApp -->

Removing App Snippets

Apps often create snippet files that remain after uninstallation. These need to be removed along with any references to them.

Finding App Snippets

1. 1.In the theme code editor, open the Snippets folder
2. 2.Look for files with app names or unfamiliar prefixes
3. 3.Open suspicious files and check if they reference the uninstalled app
4. 4.Search your entire theme for references to these snippets before deleting

Safe Removal Process

• 1.Remove all include statements referencing the snippet from other files
• 2.Delete the snippet file itself
• 3.Preview your theme to ensure nothing is broken
• 4.Check the browser console for new errors

Cleaning Asset Files

Apps may add JavaScript and CSS files to your theme's assets folder. These files continue loading even after the app is removed.

Identifying App Assets

Open the Assets folder in your theme code editor. Look for files that:

• •Have app names in their filename
• •Were created around the same time the app was installed
• •You do not recognise as part of your theme

Before Deleting

Search your entire theme for references to the asset file before deleting. Use the theme editor's search function to find any link or script tags referencing the file.

{{ 'app-name.css' | asset_url | stylesheet_tag }}
{{ 'app-name.js' | asset_url | script_tag }}
<script src="{{ 'app-name.js' | asset_url }}"></script>

Verification and Testing

After removing code, verify that your store works correctly and that performance has improved.

Testing Checklist

• 1.Preview your theme and navigate through all page types
• 2.Check the browser console for new JavaScript errors
• 3.Test the checkout process with a test order
• 4.Verify all remaining apps still function correctly
• 5.Run PageSpeed Insights before and after to measure improvement

Network Tab Verification

Re-check the Network tab in DevTools. Confirm that the removed scripts are no longer loading. Failed requests should be eliminated.