Why is my mobile speed score so much slower than my desktop score?

New Member
4 0 0

Hi, I am new to shopify and just learning about speed scores. Can someone shed some light on why my mobile speed score is SO much lower than my desktop speed score? I'm really confused by this. Thank you!!


Shopify Partner
26 0 9

It's normal to have a slower mobile loading speed than desktop because mobile devices have slower processors compared to desktops.

Based on your Google Page speed insight report, you have many javascript codes that impact your store performance.


If you want more insights about Shopify speed optimization, I recommend you to check out this guide 

Hi @pickwickandelm, I'm Richard - CRO Expert of PageFly

Mobile PageSpeed scores vary primarily because of these variables  from desktop PageSpeed scores: Mobile computers typically have slower processors.  At slower pace, PageSpeed Insights activates the cell network. There are device-specific CSS rules for mobile devices (re-sizing images, viewport size, etc.). That's the reason why your mobile score is lower than your desktop one.

Here are some tips I think would be super useful to better your mobile speed:

1. Use compressed images.

Note the size of your photo files. The optimal weight of the uploaded images shouldn’t exceed 150-200 KB. In order to compress images online, you can use free tools like jpegmini.com.

2. Simplify your web design.

3. Keep use of custom fonts to a minimum.

4. Activate Google AMP.

AMP – Accelerated Mobile Pages – is an open-source coding standard that allows you to design mobile friendly websites. AMP enables fast web page rendering, even when the network connection is really slow. Implementing it can significantly increase the users’ convenience and speed up the website loading time.

5. Minimizing the number of redirects on the site

6. Minifying the codeCode minification means simplifying the code and getting rid of any unnecessary characters without changing the functionalities and operation. It also improves the website loading time. By deleting the extra part of the code, you reduce the page weight which results in speeding up the loading time of the site.


Hope that my recommendations would be useful for you. Furthermore, you can check this article  to optimize your store speed.

Please like if you find my comment helpful for you. Thank you so much.



CRO Expert at PageFly - Advanced Shopify Page Builder - Empowering 90.000+ active merchants.

Check our Evergreen Guide on Moving Your Brick-n-Mortar Store Online.

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This is an accepted solution.

Hello @pickwickandelm 

You need to work on your website performance’s speed with following point that I have mentioned below.
Low mobile page speed may kill your traffic and affect your conversion.

In order to Improve website speed you need to:
- Remove unnecessary code on a high priority basis.
- Compressed images or Defer off-screen images.
- Web Pages need to be Minify.
- Reduce JavaScript execution time
- Minimize main-thread work
- Beware of excessive liquid loops
- Decrease thumbnail image size
- Weigh the benefits of installing another app

By fixing these issues, your website speed score can definitely improve. For more details please check and select the plan you wish to select -

If anything is missed out or unclear then don't hesitate to ask
Thank You!

If helpful then please Like and Accept Solution. Free Website Review and advice for sale from Hire us
Shopify Conversion Experts | Shopify Private App | Custom Theme Development | Custom Modifications In To Shopify Theme | Shopify SEO | Digital Marketing | Site Speed Optimization | Performance Site Audit
For Quick Chat Whats app | Email: pallavi@oscprofessionals.com | Skype : oscprofessionals-87
New Member
7 0 0

Hello, Oscprofessional,

I am facing excatly the same problem described by pickwickandelm. I have talken some screenshots again today and they are telling me, that there are obviously some problems, however I am not an IT person. My question is: Could you please have a look at those screenshots and check what the problems are and how to fix them.

I would appreciate to receive your estimation forecast on the cost and time frame to fix these problems. Obviously they only come up in the mobile version. 

Since I am new to Shopify, I am asking, whether this will go on the account of the 60 min shopify support, since to my understanding the problems are connected to the shopify Theme (Debut). Is that correct ? If so, how to arrange that with Shopify ?

Thank you for your response


Best regards  Sumageza

Sumageza On mobile version 1On mobile version 1On mobile version 2On mobile version 2On mobile version 3On mobile version 3On mobile version 4On mobile version 4On Desktop version 1On Desktop version 1On Desktop version 2On Desktop version 2On Desktop version 3On Desktop version 3On Desktop version 4On Desktop version 4