Why is Total Blocking Time higher on mobile and how can I reduce it?

[Derek_Bradley]

Hi folks, I'm running my site through Google PageSpeed Insights at present...

I'm getting excellent results for all metrics on desktop, and results for most metrics on mobile are good (FCP: 1.0-1.5s; LCP: 1.5-3.8s; CLS: 0.045). However, the total blocking time is ranging from 370ms to 1400ms (only from 0 to 50ms on desktop).

Any idea why TBT is so much larger on mobile than desktop and if there's any way that I can reduce it?

I've already removed apps that I don't need, and only have a small selection of apps installed that I consider to be essential...

Thanks

[INA_MSWEB · Accepted solution]

Hi @Derek_Bradley 

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

Here are the 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