Guide

Shopify theme slow after uninstalling apps? How to fix it

Short answer

Uninstalling a Shopify app does not always remove the code it added to your theme. Leftover scripts, stylesheets and snippets can keep loading on every page. Find them in the Network tab and in a duplicate theme's code, remove them from the copy, test, and compare PageSpeed Insights before and after. An app such as ThemeSweep can list the leftovers for you.

Why it happens

Uninstalling an app does not always remove the code it added to your theme. Script tags, stylesheets and snippets can keep loading on every page. Apps that use Shopify theme app extensions are removed cleanly; older apps that edited theme files often are not.

Leftover code is one cause of a slow theme, not the only one. Large images, apps you still use, many third-party tracking scripts and heavy theme features also slow pages down. Check the Network tab before you assume the old apps are to blame.

Check whether old app code is still loading

  1. Open a product page in Chrome, press F12 and reload with the Network tab open. Look for scripts and stylesheets loaded from the domains of apps you no longer use.
  2. In Online Store > Themes > Customize > App embeds, switch off embeds for apps you have removed.
  3. Duplicate your live theme. In the copy, open Edit code and search layout/theme.liquid, the snippets folder and the assets folder for each old app's name.
  4. Note what you find. Check where each snippet is rendered before you delete it, because some are shared with apps you still use.
  5. Run PageSpeed Insights on the same product page now, so you have a number to compare with after the cleanup.

Fix it safely

  1. Remove one old app's code at a time on the duplicate theme.
  2. Preview the copy and test product pages, cart and the way into checkout.
  3. Run PageSpeed Insights again on the same page.
  4. Publish the copy when it works. Keep the old theme until you are sure.

The full by-hand method is in our guide to removing leftover app code from a Shopify theme.

Doing it with an app

ThemeSweep, made by us, scans your theme read-only and lists code that uninstalled apps left behind, with the likely source app and a confidence level for each finding. You choose what to remove. It makes the change on a duplicate theme for you to preview and keeps a file backup with one-click rollback. It does not promise a speed score, and it can miss a script tag left in layout/theme.liquid, so check that file too. Other apps do similar jobs; see the apps compared.

Common questions

Why is my Shopify store slow after I uninstalled apps?

Uninstalling an app does not always remove the code it added to your theme. Script tags, stylesheets and snippets can keep loading on every page. Apps that use Shopify theme app extensions are removed cleanly; older apps that edited theme files often are not.

How do I check whether old app code is slowing my theme?

Open a product page in Chrome, press F12 and look at the Network tab for requests to domains of apps you no longer use. Then search layout/theme.liquid and the snippets folder of a duplicate theme for those apps' names. Run PageSpeed Insights before and after any change.

Will removing leftover app code make my store faster?

Only if that code still loads on your pages. A leftover script that runs on every page adds requests and work for the browser. An unused file that nothing references costs nothing at load time. Measure with PageSpeed Insights before and after; ThemeSweep does not promise a speed score.

Is it safe to delete old app snippets from my theme?

It is safe if you work on a duplicate theme, remove one thing at a time and test product pages, cart and checkout before publishing. Some snippets are still used by other apps or by your own customisations, so check where each one is rendered before deleting it.

Scan your theme

ThemeSweep's Free plan includes unlimited diagnostic scans and one single-finding cleanup. Paid plans start at $9.99 a month. See pricing.

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