Which Ranking Factors are Important for Mobile Sites?


Five months after Google’s mobile friendly update, it hasn’t quite turned out to be the ‘mobilegeddon’ that some predicted.

However, it has started to make an impact, as some of the data from a new Searchmetrics’ mobile SEO report shows.

For example, the percentage of mobile friendly sites in the top 30 results on Google has increased since the beginning of the year.

  • Prior to the mobile-friendly update, 68 percent of ranking URLs were found to be mobile-friendly. 
  • This share increased to 71 percent after the update.

The chart below paints a similar picture:


Essentially, there have been small movements, and it seems Google is trying to push sites towards mobile gradually. I imagine that may change after a while, and perhaps we’ll see a stricter approach in future.


Given the growth of mobile, sites shouldn’t have needed a new Google update to persuade them to optimize for mobile users. Their own customers and site analytics should have provided the answer.

On the other hand, if you didn’t have a mobile site before April 2015, there was little need to rush one out in a panic. Indeed, I’ve seen examples of sites which have done exactly this and harmed their own sales or rankings.

Mobile Ranking Factors

Here are some of the factors the study looked into. Searchmetrics looked at correlations between possible ranking factors and the appearance of the mobile SERPs. 

User Experience

Google is using more UX related factors in search rankings generally, and a good user experience is perhaps even more vital for mobile sites, given smaller screen sizes and variable mobile internet signals.

It has also been continued to clamp down on features which detract from mobile user experience, like those pesky app interstitials

The study finds a correlation between UX factors, such as images, and mobile rankings.

For example, the average number of internal links is much lower in the mobile then the desktop results, as shown in the chart below:


Space between links on mobile sites is important to avoid mistaken clicks from users, and is also something Google uses as a factor in its mobile friendly test

Here are some the ranking factors the study found to be important:

  • Larger font size 
  • Both responsive design and dedicated mobile versions of sites (m.domain.tld or mobile.domain.tld) rank in the mobile SERPS 
  • Less structural and interactive elements; unordered lists used more often, but with less bullets than in desktop 
  • Fewer ads 
  • Fewer internal links 
  • Fewer images than desktop.

Technical Factors

Speed is a massive factor, so sites need to minimise file sizes to improve page load times. The study found that the average mobile page file size was found to be around 25 percent smaller, allowing faster load times.

Meanwhile, just five percent of mobile pages make use of flash design which is not widely supported by mobile devices, compared with 14 percent of desktop pages.

As the chart shows, the difference in page loading times between desktop and mobile is very clear.



Thanks to smaller file sizes, mobile pages load more quickly, in some cases by around one tenth of a second.

  • The average loading time in the mobile top 30 is 1.17 seconds.
  • The top 10 load more quickly, with an average time of 1.10 seconds. 


  • The study found that backlinks were less of a ranking factor than on desktop. 
  • The percentage of nofollow backlinks has increased this year, but remains well below the desktop value.  
  • Mobile results are linked much less frequently to news pages, which can in part be attributed to the separate mobile versions of websites (their desktop counterparts are the ones typically linked to news sites). This trend is also decreasing compared to desktop. 

In Summary

It’s important not to draw too many conclusions from one study, just five months or so after the mobile update, but it seems that Google’s mobile rankings are in a transitional stage.

Rather than the apocalypse some predicted before the mobile update, we seem to be seeing a gradual change in rankings, and more importance placed on user experience when ranking sites.

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