Google PageSpeed #
The main difference in the Google PageSpeed results between desktop and mobile is due to the way they’re tested.
How is the mobile PageSpeed score tested by Google? #
The mobile test is run with internet connection limits and a relatively slow CPU. Currently, Google PageSpeed loads the web page as if it’s on a mid-tier device (Moto G4) on a mobile network. The mobile network has these limits:
- Latency: 150ms
- Throughput: 1.6Mbps down / 750 Kbps up
- Packet loss: None
Why is the mobile PageSpeed score low? #
Given these constraints, if your website is JavaScript-heavy, the less powerful mobile device—when compared to a desktop—will parse and process JavaScript much slower. This leads to a longer load time. It’s important when optimizing your site for mobile that you ensure there is no unused JavaScript and that any being used is well optimized.
How to improve a low PageSpeed score? #
You can optimize the site with our Website Acceleration Suite, part of the free StackCP CDN. Use the JavaScript section to minify and optimize the JavaScript for the site and the image optimization section to automatically create appropriately sized images for the mobile devices loading the site.
However, this won’t always get you a perfect score on mobile. This is because our tools won’t remove JavaScript from your site, and Google PageSpeed Insights will still give a lower score for any unused JavaScript on the page.
In most cases, to get a better score, you’ll need to make changes to the website’s code, ensuring that all JavaScript being loaded on any page is being used by that page.
