Why is my website slowing down all of a sudden?

Technical Q&A

Topic summary

Sudden site-speed drop on a Shopify store; PageSpeed Insights isn’t revealing a clear cause, and the owner seeks quick fixes.

  • A GTmetrix report link and screenshot were shared to baseline performance; the responder asked how much improvement is desired before advising further.
  • Recommendations include: remove leftover JavaScript/CSS from uninstalled apps, enable GZIP compression, compress/minify assets, limit/optimize apps, use a single hero image, and apply lazy loading only below the fold. AMP (Accelerated Mobile Pages) was suggested to speed mobile by serving cached pages.
  • A concrete fix addresses an LCP (Largest Contentful Paint) warning: the hero (above-the-fold) image was lazily loaded. In Shopify, edit image-banner.liquid to change the image loading attribute from ‘lazy’ to ‘eager’ for the hero image to avoid delaying LCP.

Outcome/status: No confirmation of resolution yet. Actionable next steps are provided, with priority on correcting hero image loading behavior and cleaning unused scripts; the thread remains open.

Summarized with AI on January 18. AI used: gpt-5.
1

Hello,

my site has been experiencing issues as of recently regarding site speed. Before, my site had issues with unused apps and large images that needed to be sized down. Now, I can’t find a specific issue with what’s making my site slow all of a sudden.

I use PageSpeed Insights to analyze whatever’s going on in the back/front end. It’s not really telling me (or rather I can’t discern) the main issues to fix.

I have been trying out apps to see if they’d work for our store, but I always uninstall apps that my store won’t go through with.

My store’s site is wooahkoco.com

Any help would be appreciated.

2

What would be the quickest, straightforward methods to improve site speed ASAP? Just a few quick fixes.

1 Like
3

Hello

I hope you are doing well.

I have checked with the performance of your site speed:https://gtmetrix.com/reports/wooahkoco.com/dAaKI5pa/

https://prnt.sc/P8Lhgcz6HFmY and here is the screenshot for that. So you can tell me how much performance you need to increase it? So i can suggest for you.

4

Hello Davemdns,

Thanks for reaching out to the community!

There can be various causes for the sudden increase in the loading time of your website. Here are some suggestions for you:

  1. Remove Unnecessary JavaScript and CSS: Many times, when you remove or uninstall the apps from your website, they leave residue in the form of JavaScript and CSS, which are unnecessary for the website. All you have to do is assess the website, identify the unnecessary scripting, and remove it from the website.
  2. Implement AMP: Accelerated Mobile Pages or AMP is an open-source HTML framework by Google, which allows Google to store the cached version of the website in the server to reduce the loading of the website on mobile devices.
  3. Use GZIP: You can use GZIP for textual compression of JavaScript and CSS of the website, which can make the scripting on the website lightweight.
  4. Implement Lazy Loading: Lazy loading is the technique, in which certain resources on the website are selected whose waiting time to load is increased to allow the important content of the website to load quickly. This technique can be used for advertisements and big images on the website.

Hope it helps!

Leesha

SEOKart

1 Like
5

Here’s one quick fix:

One of the red marks/warnings in the PageSpeed Insights test Diagnostics section is the all-too-familiar: “Largest Contentful Paint image was lazily loaded”.

While it’s important to lazy load images, this should not be done for images above the fold, only below. So, the lazy loading for your hero image needs to be disabled.

Here’s how to quickly do that:

  1. Go to your store’s dashboard and click “Themes” under “Online Store”

  2. Look for the “Current theme” section and click the 3 dots next to the “Customize” button, and then click “Edit code” in the pop-up/context menu.

  3. In the left column, search for “image-banner.liquid”, this will bring up the file where you’ll need to make a small modification

  4. Open the file

  5. Find the first line of code that says: “loading: ‘lazy’,” (without the double quotes) and either delete the line or replace ‘lazy’ with ‘eager’ (be sure to keep the comma after ‘eager’).

    That’ll take care of the LCP Lazy loading issue for you.

6

Hi @davemdns

I hope you are doing good and welcome to the Shopify Community!
I am San from MS Web Designer.

For Improving Shopify Store Load Speed and Performance, you need to optimization your store.

Few Tips to Speed Up your Shopify store-

  1. Use compressed images
  2. Optimize use of Shopify apps
  3. Implement AMP
  4. Consider Professional Help
  5. Use a single Hero Image
  6. Minify Js/Css files

Regards,

San

7

Hi , @davemdns
When a store slows down suddenly, the cause is almost always a recent change rather than the platform itself. Reviewing what was added or modified just before the slowdown usually leads to a quick resolution.

Most common causes of this :

Apps and integrations
Newly installed or updated apps often add JavaScript that loads on every page. Remove any apps that are no longer essential and test site speed after each removal to identify the impact.

Third-party scripts
Live chat, review widgets, tracking tools, and marketing scripts can block page rendering if they load too early. Non-critical scripts should load after the main content is visible.

Images and media
Large images or newly added videos can significantly affect load times, especially on mobile. Replace oversized images with optimized versions and avoid heavy media above the fold.

Theme or layout changes
Adding multiple sections, animations, or custom code increases DOM size and slows initial rendering. Remove unused sections and simplify above-the-fold layouts.

Mobile performance
Mobile devices are more sensitive to heavy scripts and large layouts. Reduce animations and enable lazy loading for images where possible.

< script >
document.querySelectorAll(‘img’).forEach(img => {

img.setAttribute(‘loading’, ‘lazy’);

});

< /script >

Alternatively, if you prefer not to diagnose sudden performance drops manually, a performance optimization app such as Website Speedy helps identify recently added scripts, large assets, and other changes that commonly impact page speed.

(Disclaimer: We are the developers of this app.)