If you work in the realm of digital publishing or web development, you should be aware of Google’s Page Speed Insights. Page Speed Insights is a tool developed by Google that analyzes the content of a web page and produces suggestions to make the page faster than it currently is.
More importantly, this tool also provides tips and suggestions for each version of your website, mobile, and desktop. This way, you or your development team can see where the problem is and focus on what is important, i.e. fixing the mobile version first and then improving the desktop one, or vice versa.
But this is not only valid when using Google’s Page Speed Insights tool. In fact, most website analyzing tools have a version of this test – based on Google’s of course – that provide you with the same information.
So whichever tool you use, when you enter a website URL, you will find that there is a difference between the desktop Page Speed score and the mobile Page Speed score. An while this is expected and perfectly common, it’s interesting to understand why it happens. So, let’s take a look.
Why Mobile & Desktop Page Speed Insights Scores Are Different
To summarize, there are three main reasons why Mobile & Desktop Page Speed Insights scores are different:
- Page Speed Insights tests the cell network at a slower speed;
- Mobile devices have slower processors;
- Mobile devices have specific CSS rules (image resizing, etc.)
Firstly, Page Speed Insights, by default, always simulates the mobile version of the website/webpage loading over a 3G connection. Without checking “simulated throttling” (exclusively available to Google Lighthouse), the desktop and mobile scores for your website should not differ too much.
Secondly, Mobile Page Speed Insights scores are rendered in different browsers that have more to account for. Also, mobile devices have CSS rules that are specific to a device, such as an image resizing, etc.
That is why it is standard practice for most mobile devices to re-size images in the browser. And that is also why it emphasizes the importance of avoiding mobile optimization errors that will slow down your website even further. Generally speaking, however, scores should not differ too much if they are both tested on the same connection speed.
Mobile scores usually aren’t any slower if they are tethered to a wifi connection, but Mobile Page Speed Insights, and Lighthouse, are both loaded over a 3G connection, hence a lower score.
Bonus tip: If you run a Google Lighthouse performance audit, use the incognito/private mode of your browser. Private browsers run without any extensions (unless manually enabled), whereas normal browsers have extensions enabled, which can affect your speed score. If you are using Page Speed Insights, there is no need to run the test in incognito/private mode.
Why is Mobile Page Speed important?
For years now, Google crawlers have focused specifically on mobile versions of websites, including their page speed and performance. However starting 2019, the crawlers only go for the mobile version, resulting in a plethora of issues for web owners who have not considered optimizing their sites for mobile.
Mobile indexing issues include problems with indexed pages, but just as important, the page speed, performance and implicitly the user experience provided by your website for mobile users. And since over half of the web traffic comes from mobile devices, one can understand how low mobile pages speed is a problem.
Additional Important Information On Page Speed Insights Scores
Page speed is an issue that most publishers struggle with, the average Page Speed Insights score is 60 for Desktop and 40 for Mobile. That’s why we have created an App and outlined some general page speed tips you can implement, that will help you increase your page speed score.