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Mobile Page Speed Update Is Live: Is there an Immediate Impact?

Page Speed Update, announced 6 months ago, has started to be rolled out on July 9, 2018. We analyzed one million pages in mobile search results to see if page speed has already started playing a role in mobile rankings.

Starting from July 9, 2018, Google Mobile Page Speed Update has started to be rolled out to all users. Google first made the announcement about the coming update in January, 2018, and for six months the SEO industry has been anticipating the changes.

In April, we ran the first round of our experiment to track correlation between page speed and the position in mobile SERPs before the update. Back then we discovered that a page's average Page Speed Optimization Score had a significant correlation (0.97) to its position in SERPs, but FCP (First Contentful Paint) and DCL (DOM Content Loaded) did not.

We repeated the experiment, preserving the same methodology, a week after Google announced the update started being released.

Over the course of 3 days, July 14-16, 2018, we looked at 30 positions in mobile SERPs for 33,500 queries (give or take) to get a list of 1,000,000 URLs. For each URL, we collected Optimization Score, Median FCP, and Median DCL. As a result, we've got 1,000,000 rows of data to analyze. You can access the raw data here. The keywords, randomly taken from the Russ Jones and Grepwords keyword list of top high paying CPC, AdWords and AdSense keywords, cover a wide range of query categories.

Methodology highlights

Keywords: ~ 33,500
Experiment date: July 14-16, 2018
Positions in SERPs: 1-30
Search results: 1,000,000 pages
Metrics: Optimization Score, Median FCP, Median DCL.

Here's what we've found.

Mobile Page Speed Experiment Part 2: The results

Result 1. The correlation between a page's average speed Optimization Score and its position in SERPs remains the same: 0.97.

There haven't been any changes for the correlation between a page's average speed Optimization Score and its position in SERPs. It remains on exactly the same level: 0.97.

Result 2: The average Optimization Score for top 30 positions has grown by 0.83 Optimization Score points.

Compared to the results in April, web pages got 0.83 extra Optimization Score points on average in July:

As you can see, the growth has been steady for all pages regardless of their positions in Google:

Result 3: There's still no correlation between the position in mobile SERPs and the median FCP/DCL metrics.

We haven't seen any significant changes when it comes to FCP /DCL analysis. The overall picture remains much the same with slight fluctuations.

Result 4: The average FCP and DCL metrics for top 30 positions have grown insignificantly.

On average, FCP has declined by 0.030 seconds and DCL has declined by 0.028 seconds:


The main conclusions of this experiment are:

  1. Improving the performance of web pages is on the rise industry-wise. For 3 months only, an average web page, ranking on positions 1-30 in mobile search, has been improved by 0.83 Optimization Score points. In other words, the standards are increasing, and the time to join the race is now. You can start working on your Optimization Score following these Google's recommendations.
  2. The correlation between the position in mobile SERPs and the average Optimization Score remains extremely high: 0.97. This provides support to the previous statement: working on your Optimization Score is crucial.
  3. There's still no correlation between the position in mobile SERPs and the median FCP/DCL metrics. The growth of average FCP/DCL metrics before and after the Page Speed Update has been minor: 0.030 seconds and 0.028 seconds respectively. Thus, there has hardly been any impact on search results a week after the Page Speed Update.

I'd like to point it out a bit further that the most important thing to work on right now is Optimization Score. Both the April and the July experiments clearly show that Optimization Score has an impact on mobile rankings. Moreover, the industry standards for the expected score are on the rise.

Raw data for this part of the experiment is available here. We'll continue to take measurements to see how the situation changes.

P.S. On September 28, I'll be sharing the results of this experiment at BrightonSEO as part of my presentation Winning with Mobile Page Speed: Killer Technologies, Tools, and Tips. If you have plans for BrightonSEO and you're keen on the topic, hope to see you there.

By: Aleh Barysevich
Co-founder and CMO, SEO PowerSuite