Mobile page speed is important, but not (yet) for SEO

There are plenty of good reasons to make your mobile site fast, and Google just reminded us of them with their new industry benchmarks for mobile page speed. Among them:

• Improving conversion rate and increasing profit, as 40 percent of consumers will leave a page that takes longer than three seconds to load.

Source: Google/SOASTA Research, 2017

• Customer retention, as 79 percent of shoppers who are dissatisfied with site performance say they’re less likely to purchase from the same site again.

But is SEO one of those reasons? Will businesses that optimize their Google page speed score to 100/100 on mobile be able to rank higher than businesses that don’t?

The answer to the first question is “yes,” in the sense that Google has said that speed is a ranking factor (and has been since 2010), and that this year they will use the speed of your mobile pages instead of desktop when determining your mobile rankings.

But it’s not clear that this is true in practice today, or that businesses that optimize their Google page speed score on mobile will rank higher than businesses that don’t.

If this were the case, the sites with the most organic search traffic would also be the fastest, but this clearly isn’t the case.

I ran the top 1,000 sites from SEMrush’s list of sites with the most organic traffic through Google’s Page speed and Mobile-friendly tool, and 800 of them went through successfully.

The good news is that 93 percent of these top sites were at least mobile-friendly. This is up from 40 percent of the top sites prior to Google’s mobile-friendly update in 2015.

But these sites are not as fast as they are mobile-friendly.

Just 2 percent of these top sites scored between 90 and 100 on Google’s mobile page speed test, and the average page speed score was 55/100.

Source: SEMrush top-ranked sites by mobile page speed score

Desktop sites were faster, but not by much. Just 4 percent of these top sites scored above 90, with the average score being 67.

Source: SEMRush top-ranked sites by desktop page speed score

The average site in Google’s study took between seven and 11 seconds to load. When you consider that a site that loads in nine seconds on mobile gets a page speed score of about 60, it seems that top-ranked sites are very similar to other sites that don’t rank well when it comes to mobile page speed.

What this means is that at the moment, page speed on mobile is much less important than a number of other signals that determine ranking. You may want to make your pages faster in order to improve conversion rates and customer retention, but it likely won’t help your SEO.

Does this mean you shouldn’t care about mobile page speed?

Before you go running into your boss’s office shouting, “STOP THE MOBILE PAGE SPEED PROJECT!!” there is one other thing that I will leave you with.

With the mobile-first index, Google will start using your mobile page speed for ranking, if they’re not doing so already. Speed is so important to them that they’ve taken it into their own hands with the AMP project, giving sites a way to display their content quickly on mobile. Most of the search traffic on Google is mobile, and as we’ve seen with Mobilegeddon, they are not above incentivizing webmasters with ranking increases if they want to change the face of the web.

With that in mind, I’d recommend the following to SEOs thinking about the impact of mobile page speed on ranking:

Increasing page speed for mobile searchers visiting your site shouldn’t be a top priority for SEO at the moment. There’s plenty of evidence that increasing page speed is good for your bottom line, which can increase the quality of SEO traffic you receive, but there’s no evidence that mobile page speed is a significant ranking factor at this time. Make your site as fast as you can, but don’t deprioritize other proven SEO tactics to get a perfect score on the mobile page speed test.

Mobile page speed, like mobile-friendly sites in 2014, could become a more significant ranking factor in the future, especially given the impending rollout of the mobile-first index. If it does, it’s likely that Google will make an announcement, as they did with the mobile-friendly update, at which point you should put resources towards making your native site faster.

In the meantime, prepare for it by making your native site as fast as you can without diverting resources from other projects, investing in AMP where it makes sense and helping whoever in your organization is responsible for conversion optimization to secure the budget by sharing Google’s research on page speed impact on conversions and customer retention with them.