Mobile First Sites: The Need for Speed

In Part I of this series about the design of mobile optimized websites, we explored “the lay of the Googleland”, i.e. the new rules for mobile sites as a function of changing expectations by visitors and evolving requirements by Google.

In this new instalment, we will look at the all-important criterion of speed, and its impact on search engine optimization and visitors’ reactions to your site.

First, let’s take a quick trip to memory lane to understand where we come from…

Google’s romance with mobile sites

Google’s infatuation with speedy mobile sites is hardly a historical factor: by this, we mean that Big G did not concern itself with mobile site speed until some time in 2015.

Up until a few short years ago, Google was actually much more concerned with mobile content than with mobile speed. Web designers at the cusp of technology had foreseen the mobile (r)evolution and pruned down the mobile version of their clients’ websites to give visitors a better User eXperience (UX) through faster speeds on slow mobile networks (2G, 3G, even early 4G). But never mind, folks, Google’s engineers were warning designers that they “had to provide mobile users an experience as rich as that provided to desktop users”… or else.

Since Google was threatening us with SEO penalties if we did not cram mobile versions with the same information as the desktop versions, we had to find ways to display volumes of information in ways that would make sense for mobile visitors, and avoid cluttering our mobile real-estate with irrelevant data.

Google did not focus on speed until late in 2016, well after social media platforms had changed mobile user’s browsing habits to “infinite scrolling”, and 6+ months after Bing released a watershed study on the browsing habits of local visitors: this study clearly showed visitor traffic to local businesses’ websites had reached 50% of their total traffic. Google was completely missing the mobile revolution, just as it had totally missed the social network revolution with the constraints imposed on its Google+ platform (letting Facebook run circles around them).

That blindness was all the more strange since Google has invented the concept of “local search results” back in 2006, way-way-way before anyone else had a clue it would become THE way for small local businesses to be discovered in search results (on an equal footing with the big players). It goes to show Big G is not a monolithic beacon of light: rather, it looks like a bunch of disrelated units that don’t act in sync. Some of its teams are freakin’ brilliant, others are as tone-deaf as bricks.

Speed is Google’s new black

Be it as it may, Google’s local search team (today, “Google My Business”) must have woken up from deep slumber one day and realized that mobile search had become a thing. They published a short paper backing up Bing’s previously published research: mobile browsing accounted for over 50% of the visitor traffic received by local businesses.

Suddenly the Google engineering team started to observe mobile users’ habits, “discovering” in the process that the vast majority of mobile sites would take 10-15 seconds to download on a mobile home screen. (We had been aware of the issue since… 2012).

Having decided that speed was the new black, Big G announced its next move way in advance, to give webmasters, theme authors and plugin developers time to adjust their speed specs. The next major algorithm update related to mobile speed was rolled out between June 2018 and early 2019.

Mobile First indexing

First question: What is it?

In Google’s own words:

“Mobile-first indexing means Google predominantly uses the mobile version of the content for indexing and ranking. Historically, the index primarily used the desktop version of a page’s content when evaluating the relevance of a page to a user’s query. Since the majority of users now access Google Search with a mobile device, Googlebot primarily crawls and indexes pages with the smartphone agent going forward.”

 

There are 2 important parts to this explanation:

• “Google predominantly uses the mobile version of the content for indexing and ranking”
  This means that the positions of your website in the search engine result pages (SERPs) are primarily determined by its mobile version.
• “Googlebot primarily crawls and indexes pages with the smartphone agent”
  This means that the Googlebot that scouts your site is specifically designed to look at it with the “eyes” of a smart phone. In other words, if it’s slow on a mobile network, you will be penalized in the search results.

In implementing Mobile First Indexing, Google continued to insist that mobile sites that did not mirror their desktop content would risk a traffic loss (stemming from a deranking).

Make sure that your mobile site contains the same content as your desktop site. If your mobile site has less content than your desktop site, consider updating your mobile site so that its primary content is equivalent to your desktop site. You can have a different design on mobile to maximize user experience (for example, moving content into accordions or tabs); just make sure that the content is equivalent to the desktop site, since almost all indexing on your site comes from the mobile site.

WARNING: If it’s your intention that the mobile page should have less content than the desktop page, you can expect some traffic loss when your site is enabled mobile-first indexing, since Google can’t get as much information from your page as before. Instead of removing content, consider moving content into accordions or tabs to save space.

Source: Google

NOTE: The last advice consisting in tucking content in accordions and tabs may sound “thoughtful” but that’s not the way mobile users browse content. If you want your content discovered on mobile, make it obvious and don’t resort to complex navigation schemes like tabs that are unwieldy in the small viewport of a smart phone.

In any case, if you were not aware that “mobile first” had become the new indexing standard of Google, and your mobile site matters very much, consider yourself updated. What’s next?

Core Web Vitals

Google is in a long-term effort to reduce the total processing power required from its server infrastructure to index the web and serve it to Google users. From a financial standpoint, indexing and handling trillions of pages and exabytes of data (that’s 1 000 000 000 000 000 000, or 10.18 Bytes) requires a huge quantity of processing power and electricity. Big G, as the energy-conscious business it portrays itself to be (or maybe more prosaically, as a profit-conscious business) is on a crusade to decrease its power usage.

To this end, holding web designers accountable for how speedily their mobile sites perform is a great idea. Reduce the weight (in KB) of your pages, shorten the distance it takes to reach the website (via content distribution networks), minimize the number of HTTP calls to your server, and simplify/minify your stylesheets and JS, and your site will be much faster to crawl and much faster to serve. Your visitors will love, Google will love, everybody wins. That’s basically the rationale behind the new kids on the block: the Core Web Vitals.

The Core Web Vitals are a new series of speed indicators Google announced back in November 2020 and tested before rolling their implementation out at end-May 2021.

What does Big G have to say about this?

Page experience is a set of signals that measure how users perceive the experience of interacting with a web page beyond its pure information value. It includes Core Web Vitals, which is a set of metrics that measure real-world user experience for loading performance, interactivity, and visual stability of the page.

OK, so in simple terms, Google measures how fast your mobile site is, how long it takes your visitors to be able to interact with it, and how much unwanted motion the design of your mobile pages imposes on your visitors. Yes, nobody likes a page that’s slow to download, that forces users to wait until its clickable buttons become clickable, and that continues to move after it’s fully downloaded.

The Core Web Vitals were rolled out at the end of May 2021 in some markets, a bit later in others. Google had warned web designers that speed would now be a ranking factor. They didn’t lie. Slow websites have taken a hit. Faster websites have been positively impacted. We did before/after tests in several markets, and there is little doubt that today, speedy sites do better in the search results.

But just how fast?

The common answer you’ll find around the web to this question would be 3.0 seconds. But that’s not the case.

The 3.0 second target was the 2018 figure given by Google at the time they were preparing to roll out Mobile First Indexing.  As they observed that an average website was still taking 10-15 seconds to download, Google’s engineers set 3.0 seconds as the new normal. Above that number, penalties would start applying. The 3 sec rule became a popular number and the industry started to work towards that number to improve their positions in the search results.

In reality, the Core Web Vitals are a more complex set of targets. The sum total boils down to a couple of scores (mobile and desktop), but these are calculated based on the actual Core Web Vitals.

There are the 3 performance indicators your site needs to match. Here is what Google states:

The page [i.e. your site] provides a good user experience, focusing on the aspects of loading, interactivity, and visual stability:

 

• • Largest Contentful Paint (LCP): Measures loading performance. To provide a good user experience, strive to have LCP occur within the first 2.5 seconds of the page starting to load.
  • First Input Delay (FID): Measures interactivity. To provide a good user experience, strive to have an FID of less than 100 milliseconds.
  • Cumulative Layout Shift (CLS): Measures visual stability. To provide a good user experience, strive to have a CLS score of less than 0.1.

(Source: Google)

As you can see in the timings, there is no mention of a “3.0 seconds” target — even if, once again, this target is a good number to aim at for both search engine rankings and user experience.

Google has made several tools available to mesure your website performance, and understand where it may need help. The simplest testing tool to use is Page Speed Insights.

• If your website’s Core Web Vitals are already measured by Google, the results you will get from the testing tool will be real results (“field” results) gathered in the past 28 days. The scoring will also show if your website passes or fails the Core Web Vitals.
• If your website’s Core Web Vitals are not already measured by Google (for instance, your site doesn’t have any significant traffic or it is not connected to the Google Search Console), the Page Speed Insights test will give you “lab data” (not “field” data), i.e. a snapshot of your site performance. The scoring system will show you where the problems are. There is a difference between “field data” and “lab data”, but you will get a great indication of how speedy your site is, and a series of recommendations to bring it up to snuff, on all Core Web Vitals.

Correlation to user experience

There is a variety of statistics quoted on the web purporting to show a correlation between speed, user experience, and user behavior.

One of these is an Amazon paper published in 2009 showing the theoretical impact on revenues of a 100-millisecond delay in page loading time. Another paper widely quoted was published by CDN provider Akamai in 2017 exploring the impact of a 1-second delay on conversion rates (buyers/visitors ratio). Yet another one is a discussion that took place at a Web 2.0 conference in 2006 where then-Google VP Marissa Mayer described how a 0.5 second latency in search results negatively impacted search traffic.

All these “magic numbers” are to be taken with a grain of salt: the websites that quote them usually don’t dig into the conditions of the studies, and raw numbers can’t be properly interpreted without background data. Furthermore, how relevant today are studies published in 2006 or 2009?

More to the point is a paper published by audit and accounting firm Deloitte, quoting in part Google’s numbers, a section of which we reproduce here. The following table shows the change in user experience and behavior as loading time increases. For practical purposes, a delay in loading time does not seem to impact user behavior until the 1-second mark.

The scope and results of this study leave little interpretation to error. Based on a very large sampling (7.4 million user sessions) over 4 different industries (Retail, Travel, Lead Generation, Luxury), the researchers draw several key conclusions: An improvement of website speed by 0.1 second on mobile devices will favorably impact key metrics:

• Visitors progress further along the sales funnel (from browsing to checking out)
• Pageviews per session increased (depth of visits)
• Conversion rates (buyers/visitors) improved (*)
• Transaction values ($/buyer) improved

(*) Excepted in the lead generation industry where mobile conversion rates decreased.

As the mobile web gradually replaces the desktop web in searching, browsing, and buying habits, speed becomes a critical factor in the capacity of your website to make your phone ring, and transform visitors into buyers.

Free independent evaluation