There is a lot of talk about JavaScript, CSS, images affecting the speed of your Shopify store but not so much about apps. 

Is it possible that apps can slow down your shop?

In this post, I want to clear up some misconceptions with and shed some light on how our app affects site speed.  

Site Speed Really Matters

All the bells and whistles we add to the webstore are great, but customers tend to care more about page loading time than an aesthetic design or new nifty functionality. 

According to a recent study by Akamai, a 1-second page delay leads to:

  • 11% drop in the number of page views 
  • 16% decrease in customer satisfaction
  • 7% reduction in conversions
  • 1% loss of webstore’s revenue

Site speed also plays an important role in:

  • Search engine rankings
  • Overall site traffic
  • Sales

That’s not news. What has changed is that more people are using mobile devices to search for shops and buy. Mobile speed is more important than ever: the average person spends 4 hours on their phone… each day. Yowza. In 2016 Google started to split search results into two indexes – one for desktop and one for mobile. And that’s why speed is a priority for marketers and SEOs.  

Experiment Setup

Everything on your site has weight: images, files, codes, scripts. Images are the biggest culprit for slow load times. But what about applications? 

There is much debate. 

We decided to run some tests to see if actually affects performance. Want to check our test scores? Head over to the Test Results subtopic.

Step 1. Select analysis tools

Sitting by a laptop with a stopwatch as the pages load is not a convenient way to find out whether the website is slow or not. That’s why we will take advantage of website speed test tools. 

Analysis tools allow us to see performance and areas that can be improved. 

We use these tools to test our site speed:

They analyze your webstore and provide recommendations based on algorithms and a determined scoring system.

Step 2. Create a test account

We’ve created a free development store (using the Debut theme) with some bogus items so our product sections had enough images to emulate a basic store.

Can Slow Down a Shop?

After a while, we’re done: a beautiful website, with everything a Shopify store owner would need to start work 🤘

Step 3. Install Recom

We have measured site performance BEFORE and AFTER we install the app. 

Test Results

Time to see the effect of installing the app!


GTMetrix uses YSlow and PageSpeed to evaluate a website’s front-end performance, giving us easy-to-understand information.

#1. Store with NO goods 

Fully loaded time (s): 2,6

Total page size(Kb): 224

Can Slow Down a Shop?

#2. Store with NO goods, WITH

Fully loaded time (s): 1.9

Total page size(Kb): 306

Can Slow Down a Shop?

#3. Store WITH goods, WITH

Fully loaded time (s): 1,9

Total page size(Kb): 314

Can Slow Down a Shop?

The numbers speak from themselves: a Shopify store with the – Upsell & Cross-Sell app took 1.9s to load. 

After uninstalling the app, let’s test the speed again:

Can Slow Down a Shop?

The load speed is less than the results for the bare-naked Shopify store: 2,1 seconds for a fully loaded time

Why is it important to test the website speed after removing the app? 

Shopify recommends developers implement apps with no modification to the theme code. This way an app delete is guaranteed to be clean.

Usually the situation is different.

Not all app developers care about creating an app work without touching the original theme code. The end result? After uninstalling, apps leave zombie code that increases your site’s load time. passes through the first development stage of “straight-forward implementation” and doesn’t leave dead, leftover code.

Google Page SpeedInsight

This is a tool by Google and it will show us what’s causing our website to load slow. 

Google PageSpeed Insights gives you a score. If you have an amazing score, you’re doing a good job. If you have a terrible score, it will even show you what to fix to improve your speed. install after install after install after install before install before 

It’s the final test. generates a performance grade, a total load time, the total page size, and the number of requests we have on our website. 

#1. Store with NO goods 

Can Slow Down a Shop?

#2. Store with NO goods, WITH

Can Slow Down a Shop?

#3. Store WITH goods, WITH

Can Slow Down a Shop?

To sum it all up:

Clean Shopify store      511ms

With no goods, with      489ms

With goods, with       486ms

Our Comment

Based on the test results, we can confidently say that:

YES – increases the amount of data to be transferred, with little changes. 

NO – it does not slow down the website. 

Keep In Mind

Although Shopify apps are providing you with positive returns, the reality that many applications can cause conflicts with certain Shopify themes.

I am not arguing for you to stop using apps. I want to say that you should use apps that really enhance your existing site and help reach new heights. Take a look at our list of 11 must-have Shopify apps to make your choice easier.

What I’m trying to say is a few things: 

  1. Measure your site performance BEFORE and AFTER you install an app to your site. 

Apps are great – they add so much value to your online store but… Be careful when installing apps. Some applications actually might be a real trojan horse of your store. Always make sure the app has no effect on your page load speed because a slow shop scares away visitors.

  1. Delete INACTIVE or UNUSED apps.

One thing that can add extra weight to your webstore is installed but inactive apps. At least once a year, try to do an inventory of your apps and delete any ones that you no longer use. 

Our Advice

The Shopify app store is fantastic. 

But MORE apps means MORE code.

More code means a vital slowdown.

A slow webstore results in loss of sales.


#1. How to understand that these apps cause a performance issue?

You can diagnose a bad app by disabling each app, and seeing if the site speeds up. If disabling one app speeds things up significantly, then you’ve found the app that hurts the store’s speed. 

#2. How to delete the dead weight apps?

Sometimes leftovers from apps are making a great impact on your page load speeds. For that reason, we recommend you contact the app’s developer with your concerns, and ask them for help.


✌️ A Shopify store with only takes 1.9 seconds to load.

🐌 Some apps that you install add a bit of JavaScript/CSS script to your webstore that can significantly slow down your page load time.

⌛ Restrict apps that you’ll use to a minimum. Remove any apps you’re no longer using. 

💰 The Shopify app store is fantastic – keep using them but review your app list from time to time.