● Findings · October 2026 · Daniel the Tuner

How to find leftover app code on Shopify (without installing another app)

You tried an app, didn’t like it, uninstalled it. Done, right? Not always. Depending on how the app was added to your store, its code can keep loading on every page for months, slowing things down for nothing.

We checked the homepages of 1,390 Shopify stores this month to see how often that happens, and where the leftovers hide.

Three ways an app gets into your store

Whether code goes away when you uninstall depends on how it came in.

1. App embeds and app blocks. The modern way. You switch them on in the theme editor, and Shopify removes them automatically when you uninstall the app. 80% of the stores we checked use at least one.
2. Script tags. The app tells Shopify to load a script on your pages. These are normally removed when you uninstall, but not always. We found script tags still pointing at apps whose servers are long gone.
3. Code written into the theme files. Older apps, setup guides and developers sometimes paste code straight into your theme. Uninstalling the app never touches this. 39% of the stores we checked had third-party code living in their theme files (not counting analytics tags).

Not all of that third type is leftover. If you still use the app, it’s doing its job. It becomes a problem when the app is gone and the code isn’t.

What leftovers cost you

• Wasted downloads. Every shopper’s phone downloads and runs code that does nothing.
• Dead requests. 9% of stores keep asking for a script that no longer exists. The browser still waits for the answer.
• Surprises. One store we worked on had uninstalled a page builder. Its leftover code checked whether the app was set up, and once the app was gone, that check flipped and started loading a full copy of jQuery, about 90 KB, at the very top of every page, holding everything else up. Taking out two lines removed it.

How to find it, step by step

1. Make a list of apps you’ve removed. Your Shopify bills (Settings → Billing) list the paid apps you’ve had, which is a good place to start. You can’t look for leftovers if you don’t know what you’re looking for.
2. Search your live page. Open your store, view the page source (Ctrl+U on Windows, Option+Cmd+U on Mac) and search for each app’s name or domain. If it shows up, something is still loading it.
3. Check the theme editor. In Online Store → Themes → Customize, open App embeds. Anything listed there belongs to an app that’s still installed, so it isn’t leftover.
4. Search the theme files. In Online Store → Themes, open the … menu and choose Download theme file (Shopify emails you a link), then search the files on your computer for the app’s name. The usual hiding places:
   • layout/theme.liquid, often near the top of the page or just before </body>
   • files in snippets/ named after the app
   • lines like {% render 'app-name' %} or <script src="https://…app-domain…">

How to remove it without breaking anything

1. Duplicate your theme first (Themes → … → Duplicate) and do all the work on the copy.
2. Comment out, don’t delete. Wrap the leftover lines like this, so you can undo it in seconds:

   {% comment %} leftover from an app removed in 2025
     {% render 'old-app-snippet' %}
   {% endcomment %}

3. Preview the copy and test what matters: add to cart, the cart drawer, product options, reviews, the checkout button, on a phone too.
4. Publish the copy, and keep the old theme for a couple of weeks in case something turns up.
5. Only then delete the commented lines and the app’s snippet files.

Be careful with lines that mention more than one app. Theme files often have several apps squeezed into the same spot, and commenting out one line can take your chat widget or tracking down with it.

Why not just install a cleanup app?

There are apps that promise to clean leftover code for you. The hard part isn’t finding code. It’s knowing which code is truly unused, and that takes reading your theme. An app guessing and deleting theme code on its own is exactly how stores end up with a broken cart. Use one to find candidates if you like, but have a person make the final call.

How we got these numbers

In October 2026 we fetched the public homepage of 1,390 Shopify stores and ran Google PageSpeed Insights once on mobile for each. We identified apps from the code on the page (app embeds, script tags, and scripts written into the theme), using the same rules as our free check. Analytics tags were left out of the theme-code count. We only looked at homepages, so leftovers that live on product or cart pages aren’t counted, and the real numbers are likely higher. We don’t name any of the stores or apps.