Has your Shopify store started feeling slower? Before replacing your theme or uninstalling every app, it is worth finding out what is actually causing the delay.
Apps can add useful features such as product reviews, live chat, pop-ups and wishlists. They can also introduce JavaScript, stylesheets and third-party requests. This guide explains how to investigate them safely, without removing features your customers rely on.
1. Establish a baseline with PageSpeed Insights
Open Google PageSpeed Insights, enter your storefront URL and run the analysis. Check both mobile and desktop, but pay particular attention to mobile.
Test more than your homepage. Include a representative product page and collection page, because apps may behave differently across templates.
Look at the field data when available, then review the laboratory diagnostics for JavaScript execution and third-party resources. A single test is not definitive: run several tests under comparable conditions.
Understand the three Core Web Vitals
- Largest Contentful Paint (LCP): how quickly the largest visible content element appears. A good result is 2.5 seconds or less.
- Interaction to Next Paint (INP): how responsive the page is to user interactions. A good result is 200 milliseconds or less.
- Cumulative Layout Shift (CLS): unexpected visual movement. A good result is 0.1 or less.
These are user-experience indicators, not an app removal checklist. A third-party script can contribute to poor performance without being the only cause.
2. Review Shopify's available web performance reports
In Shopify Admin, open Analytics → Reports and search for Largest Contentful Paint (LCP): Over Time or other performance reports available to your store. This report appears in the example below; availability and names can vary. Report names and availability can vary as Shopify updates its interface.
Use these reports, where available, to compare real visitor experience over time. If you cannot find a relevant report, continue with PageSpeed Insights and Chrome DevTools rather than looking for an older performance summary in the Themes screen.
3. Audit your installed apps
Go to Settings → Apps and sales channels. Review the installed apps and make a shortlist of those that affect the storefront.
- Is this feature still in use?
- Does another app or your theme already provide the same functionality?
- Does the app load on every page, even where it is not needed?
- Is it essential to sales, customer support or tracking?
For example, an old promotional pop-up or duplicate wishlist feature may no longer justify its ongoing complexity. But do not uninstall anything yet: first understand what it does.
4. Inspect app embeds and app blocks
Open Online Store → Themes → Customize, then select App embeds. Review enabled integrations. Also check relevant templates for app blocks that load on specific pages.
Some apps depend on embeds for essential functionality, so avoid switching them off on your live storefront without a plan. Make a theme duplicate for layout and embed checks, and follow the app developer's instructions where appropriate. Remember that a preview may not reproduce real visitor performance exactly.
5. Investigate third-party JavaScript in Chrome DevTools
Open your storefront in Chrome, right-click and select Inspect. In the Network panel, reload the page and filter requests by JS.
Look for unfamiliar third-party domains, large JavaScript transfers and scripts loaded across many pages. For reliable investigation, test in a clean browser profile without extensions: extension-injected scripts can otherwise appear in the request list. Compare the domains with your installed apps and tracking integrations.
For deeper analysis, use the Performance panel to inspect long tasks and main-thread activity. A slow network request alone does not prove that an app is responsible for poor INP.
6. Change one thing at a time
- Record your baseline results and the pages you tested.
- Choose one non-essential feature or integration to investigate.
- Follow the app's recommended disable or removal procedure.
- Test the affected storefront functionality, including mobile, cart and checkout-related flows.
- Repeat your performance tests under similar conditions and compare results.
If you remove an app, check whether it left manually added snippets or other code behind. Do not delete unfamiliar scripts without verifying their purpose. Also be aware that real-user performance metrics take time to reflect changes.
7. Keep apps that deliver genuine value
Not every app that adds loading overhead should be removed. Reviews, accessibility features, customer support tools and other integrations may deliver meaningful benefits. The aim is to remove unused functionality, reduce duplication and load features only where they are needed when possible.
Final thoughts
A faster Shopify store does not always require a new theme. Start by measuring performance, understanding what your apps load and testing changes carefully. You can often simplify a storefront without sacrificing features customers actually use.
Need a second opinion? Michael Thomas Media helps Shopify merchants investigate performance issues and make practical, maintainable improvements.
Further reading: Shopify web performance documentation and Google PageSpeed Insights.
