Warning to All Shopify Store Owners: Beware of "Google Page Speed Hacks"

Shopify Partner
24 0 13

Dear Shopify Community,


I'm writing to you as an owner of a Shopify agency based in Germany. In the course of providing free shop analysis services, we've recently come across a concerning trend that we feel to share with you.


Beware of Page Speed Optimization Services on Platforms like Fiverr

We noticed, that some freelancers, particularly those offering services at unusually low prices, are faking page speed optimizations for Shopify stores. They're achieving this through what we're calling "Google Page Speed Hacks". The results might look impressive at first glance, but they are misleading and potentially harmful.


How the "Hack" Works

  1. Using the YETT Library to Block Scripts: These individuals are using the YETT library to block scripts. In some cases, they block ALL scripts for Linux users. This gives the illusion of a fast page speed because when Google crawls the site, it doesn't have to load any scripts. I dont know if i am allowed to post the full code, as it is harmful, so i will just post snippets for you to be able to check your themes. 

    if(navigator.platform =="Linux x86_64"){ // Code to block all files }
  2. Faking Good First Contentful Paint (FCP): Please also search for this code: <img alt="someimgname" width="99999" height="99999" style="pointer-events: none; position: absolute; top: 0; left: 0; width: 96vw; height: 96vh; max-width: 99vw; max-height: 99vh;"

Why Is This a Problem?

  • Deception: This is a deceptive practice that doesn't genuinely improve your website's performance.
  • User Experience: Customers using Linux cant do anything on your site.
  • Google's Response: Engaging in such practices can lead to negative consequences from Google.
  • Potential Shopify Restrictions: While we don't have confirmed cases yet, such practices might lead to restrictions from Shopify.

How to Detect These Practices

  • Search your entire theme for YETT_BLACKLIST.
  • Look for instances of <img width="99999" height="99999".
  • Compare your local page speed analysis with the results from pagespeed.web.dev. Significant discrepancies could be a red flag.
  • Be aware that individuals might use different methods for such deception. If you find more harmful code - it would be good do add it to this list so people can search and remove it.

Our Recommendation

We strongly recommend having your site evaluated by an expert if you suspect any foul play. It's crucial to ensure that your page speed optimizations are genuine and beneficial for all users.

If you have any concerns or need assistance, please don't hesitate to reach out.


Best regards,


 BRANDJUNG Agentur GmbH 
Spezialisiert auf Shopify & Datenmigration (DE/EN)
Replies 3 (3)

Shopify Partner
25 1 2

Yes, I have come across a few stores that have fallen for this. Sometimes, they also use code containing keywords like 'document.open' or 'document.write' or 'pDescription'

1 0 1

The YETT Library itself is not harmful, on the contrary it is a very good library to block tracking scripts that would collect data before a user's consent. However the practices that people do with it are indeed out of line, i worked with 3 stores that had the fallen to the same trick.

Shopify Partner
24 0 13

Exactly! We saw more and more stores in the past weeks that fall for this. 

 BRANDJUNG Agentur GmbH 
Spezialisiert auf Shopify & Datenmigration (DE/EN)