3 Ways to Check if You Have Zombie Code on Your Shopify Store

By Rumen Dimitrov • 3 min read

Is your site slower than usual? Well, I’m 90% certain you have zombie code. Read on to learn how to find it

The zombie consumes, but never becomes. That insatiable thirst is what makes leftover code on your site dangerous the way zombies are—it eats the resources of your mobile visitors with no intention to stop.

Less resources mean less is left for what you really want people to see—the products on your store and the benefits from having them.

You may or may not have zombie code on your store. As a Shopify store owner, here are your options to finding out:

1. Look for traces of the undead code yourself

1.1. Remember the apps you tried

If you can remember, make a list of the apps you used that are no longer present on your store. For each one ask yourself:

1.1.1. Did the app require manual installation?

Manual installation here means you or a developer edited a file on your theme to enable the app to function. Alternatively clicking a button, in an already installed app that says “Install” installs the needed code in your theme. These both count as “manual installation” and are likely to leave code that needs to be removed the same way it got installed. So, if you answered yes, you have zombie code.

1.1.2. Was this a service/app outside of the Shopify ecosystem that needed code snippet installation on your store?

If yes, you still have that code in one or more places of your store:

in your theme code
in your “Custom JavaScript code for Google Analytics Script” box in “Online Store” > ”Preferences”
in your “Additional scripts” box on “Settings” > ”Checkout”

Did you remember to remove the code after you stopped using the service? If not, congrats, you have a zombie! :)

1.2. Evaluate your website

You can look for anomalies on your website. If there is zombie code present on your store you may see it show up as leftover functionality that didn’t go away after you stopped using the app.

Here is how to check:

Load your homepage on your computer.
Look through every element, from navigation to the footer.
Do you spot something broken? Can you remember these buttons/labels/images/timers needing to be edited through an app? If you are still seeing them, but the app is not in your App list, you have zombie code that won’t go away on its own.

Repeat the same process for your collection pages, product pages, cart and info pages. No need to go through every product—look at 1-3 product pages, as they represent pages of the same type. Same is true for collection pages. Then repeat on mobile.

2. Get help to spot the Zombie

You need an experienced pair of eyes when:

you can’t remember all of the apps you tried and uninstalled (on your store, with the same theme)
you don’t have the time or experience to analyze your website

Then, the best thing you could do is ask a speed optimization expert for a speed audit and advice. After they are done you’ll get specific advice what can be improved or removed(zombie code and not) so that you speed up your Shopify store. Usually these are tasks you could perform yourself.

3. Call the exterminator

Your last option is to not get involved in this directly. If you think that your store is not as fast as it could be, contact a professional. Identifying and exterminating zombie code is a fundamental part of the work of every reputable speed optimization expert.