My websites performance issue specially on mobile

Technical Q&A

Topic summary

A website owner reports poor mobile performance (around 50 score) despite compressing images and removing unwanted elements. They’re seeking help identifying what causes slow loading times.

Main Issues Identified:

  • Heavy Total Blocking Time (TBT), particularly affecting mobile devices
  • Google Tag Manager significantly contributing to TBT
  • Excessive JavaScript execution time
  • Large image sizes
  • Potential issues with liquid loops

Recommended Solutions:

  • Select a lightweight Shopify theme
  • Remove unused Shopify apps
  • Minify JavaScript and CSS files
  • Resize and compress product images (bulk processing suggested)
  • Apply lazy loading per section (except main banner)
  • Replace GIFs with static images
  • Remove unnecessary code on high priority
  • Preload critical images

Tools Mentioned:

  • Google PageSpeed Insights and GTmetrix for performance testing

One responder offered a free website optimization audit report. The discussion remains open with actionable steps provided but no confirmation of implementation or resolution.

Summarized with AI on November 9. AI used: claude-sonnet-4-5-20250929.
1

I would appreciate any help diagnosing problems with my website, its performance on mobile is around 50 which isnt great.

I have tried to compress the images as much as possible and delete unwanted apps.

when you look at the my websites loading time, is there anything odd that cases it to load slowly? (I couldnt find anything)

https://dannicowoodworks.com/

2

Hello,

Thank you for sharing your Store URL.

Here are some proven steps that will improve your website speed dramatically for both mobile and desktop.

  • Select a light Weight Shopify Theme
  • Remove all Unwanted Shopify App ( That you have installed but not using)
  • Minify Javascript, CSS
  • Reduce the Large Image Size
  • Eliminating the halting problem in Javascript
  • Apply Lazy loading per section wherever required
  • Replace Gifs with the Static Images
  • Resize Products images using Shopify App ( for Bulk )
  • Check the page speed using Google page Insight and GTmetrix.

By fixing these issues, your website speed score can improve.
If you want a Free complete Website Optimization Audit Report (All the Actionable steps for your store), let me know .

If you have any concerns feel free to ask me!

Good Luck!
Regards,
San

3

hello @moosaes

As I can see, your website is having heavy load with Total Blocking Time(TBT). In order to Improve website speed we need to:

  • Remove unnecessary code on a high priority basis.

  • Reduce JavaScript execution time - Minimize main-thread work

  • Beware of excessive liquid loops.

  • Weigh the benefits of installing another app By fixing these issues, your website speed score can definitely improve.

I have checked your site in the Google Page insights tool. There is a low score on your website. It needs to be improved, especially on mobile devices. As I can see your website is having a heavy load with Total Blocking Time.

especially Google Tag Manager affecting heavy load on TBT

here below screenshots, you can see that’s affecting TBT

oscprofessional_0-1713763451769.png
oscprofessional_0-1713763451769.png1153×616 77.9 KB

4

  1. unlazy load your main banner

  2. preload image

  3. resize and reupload