On 9 July 2018 Google announced the rollout to all users of a new Speed Update algorithm to be used as a ranking factor in mobile search results.

Per Google, this update should "only affect a small percentage of queries" - by not serving "pages that deliver the slowest experience to users" on mobile devices.

Google offers several ways to check the loading speed of pages, including the PageSpeed Insights tool and Google Lighthouse which is available in Developer Tools in the Chrome browser.

But also buried in Google Analytics is a way to see - all in one place, for each page of a website - the Average Document Content Loaded Time (time it takes for a user to be able to SEE the page) and the Average Document Interactive Time (time it takes the user to be able to USE the page).

Here's how to find out if some of your pages are among those that "deliver the slowest experience" and which Google won't serve to mobile users:

First, log in to your Google Analytics account and in the left navigation menu click Site Speed.

In the submenu that appears, click Page Timings.

That should open a screen something like this:

Once there, click the DOM Timings link above the graph, to get the DOM Timings view.

Then open the dropdown menu on the left above the graph, which should look like this:

Remember Content Loaded Time (time for user to SEE the page content) and Interactive Time (time for user to be able to USE the page content) that I mentioned earlier? This is the place from which you can access these reports.

On that same screen, down below the graph, you should see a table of data for the first 10 of your pages. (Your Page column should contain page URLs. I've whited them out in the example to protect the innocent.)

Open the dropdown menu at the top of the 3rd column and set it as shown in the screencap above. Do the same for the dropdown menu at the top of the 4th column. Now what GA is showing for each of your first 10 pages is:

1. Average time in seconds it takes the page content to load so as to be visible to the user, and
2. Average time (expressed as a % of the overall site average) for the page content to become interactive, so the user can do something with it.

For the technically-minded, here are more precise definitions of those terms:

Avg. Document Content Loaded Time : The average time (in seconds) that the browser takes to parse the document and execute deferred and parser-inserted scripts (DOMContentLoaded), including the network time from the user's location to your server. Parsing of the document is finished, the Document Object Model is ready, but referenced style sheets, images, and subframes may not be finished loading. This event is often the starting point for javascript framework execution, e.g., JQuery's onready() callback, etc.

Avg. Document Interactive Time : The average time (in seconds) that the browser takes to parse the document (DOMInteractive), including the network time from the user's location to your server. At this time, the user can interact with the Document Object Model even though it is not fully loaded.

In the example, Pages 1 and 2 (as numbered in 1st column) jump right out as potentially slowest of the slow.

Page #1 takes 10.02 seconds to be visible to the user, and its time to become interactive is 447.08% that of the sitewide average time. Given that the sitewide average time is 1.83 seconds, 447.08% of that is 1.83 x 4.4708 = 8.18 seconds.

Page #2 is nearly as bad: 9.98 seconds to be visible, 1.83 x 4.4435 = 8.13 seconds to be usable.

To improve your site's ranking in Google searches done on mobile devices, these are the first 2 pages that you need to fix - by removing images, making image file sizes smaller, removing Flash, removing unnecessary JavaScript, or whatever.

That's a whole new subject I'll adress in a later post.