How to improve your mobile PageSpeed score

The mobile PageSpeed score of a website is usually lower than the desktop score.

In this article you can find the reasons behind this, which WP Rocket settings are most recommended, and what other concrete steps you can take to optimize your mobile site further.

Mobile conditions

First, it's important to know that the conditions under which mobile devices are used are not always optimal:

• The devices themselves have less processing power than a desktop.
• Internet connections may be slower and/or less reliable.
• Depending on the location of your visitor, they may be paying a high cost for internet access and bandwidth.

Everything takes longer on mobile. This means that any negative performance aspect, which might not be very noticeable on desktop, will be very obvious on mobile devices.

In particular, the PageSpeed mobile test is done on a slow 4G connection, on an average device. So the conditions are likely worse than your users are actually experiencing in real life.

How can WP Rocket help

WP Rocket speeds up the mobile version of the site right on activation with the automatic features and the default settings, which includes the Mobile Cache feature.

Additionally, you can further improve the mobile grade with these general guidelines:

• You have activated the WP Rocket optimizations.
• There is no excessive use of exclusions.
• The site has a good baseline performance: hosting, plugins, site content, etc.

You can also find more information on the Google PageSpeed grade does not improve article.

Optimizations outside WP Rocket

Using the above general guidelines should be enough to improve the PageSpeed grade and the Core Web Vitals. However, WP Rocket cannot solve all PageSpeed recommendations.

Given that web performance best practices are even more critical on mobile devices, below is a set of recommendations and considerations:

• Mobile pages have to be as light as possible to score highly: you have to be very selective in deciding which features you actually should include on the mobile version of your site. It’s important to understand that there will be a trade-off between having a lot of rich interactive features, and having a fast site. You have to try to find a balance.
• Reduce scripts on your mobile pages: move elements with a lot of animations or heavy scripts lower on your page so they don’t slow down the initial view of the page. For example, if you have a slider on your site, consider loading it in the middle of the page and not at the top.
• Reduce page size: Aim for less than 1MB for your mobile pages. You can do this by replacing interactive elements like sliders with a static image, or featured posts/products on the page, or the number of fonts.
• Optimize the format of your images: Use WebP or AVIF formats on your images. To do this, you can use Imagify. 
• Reduce 3rd party content: Content hosted externally can't be fully optimized. Reduce the number of ads, and don’t place them at the top of the page. Also, remove unnecessary social widgets like Instagram / Facebook / Twitter feeds.
• Keep in mind that there are some insights that WP Rocket can't resolve.