In 2017, I wrote a post about the risks of mobile SEO issues as Google’s move to mobile-first indexing approached. This post focused more on sites running M-Dots and the various issues that could arise due to Google’s plans to use the mobile version of a page for indexing. Well, we are in 2024 and although most websites are no longer running M-Dots, there are still mobile issues that can cause SEO problems. And I just recently encountered several of these issues during two different audits.
For example, while recently reviewing two websites, I came across some hidden SEO issues that were easy to miss. And these insidious problems could have a serious impact on the websites in question (especially over time). Below I want to briefly address these situations, explain why viewing your website through a mobile lens is extremely important, while also explaining how you can bring these tricky issues to light on your own website. The first part of the post contains short case studies and the second part covers tools that can help you uncover these issues. Let’s dive in.
A quick (but important) note about mobile-first indexing:Firstly, Google has completely switched to mobile-first indexing. Google’s last communication on this was on October 31, 2023, stating that most websites had successfully transitioned to mobile-first indexing. This is important because it means Google will use this mobile version of your pages for indexing purposes. Google essentially uses its Smartphone Crawler for indexing purposes. This includes content, structured data, instructions, canonicals and more. By the way, Google has a great page that explains this The most common problems You can come over.
This is why it’s incredibly important to make sure your mobile pages contain what you want to index. When Google crawls with you Googlebot smartphonethen you want to make sure everything is in place. If not, serious problems could arise, be it less content to index, missing instructions, missing or incomplete structured data, missing or incorrect canonicals, and more.
Below I will briefly discuss several scenarios where two different websites encountered an error. Both are larger sites where this could ultimately impact thousands or more URLs.
Case 1: Hide-and-seek with Canonicals (on mobile).
The first website I’ll cover has a footprint of about 100,000 URLs and has been severely impacted by several major algorithm updates over time. While analyzing the site, I noticed that some of my tools were not reporting canonical tags for a number of URLs. However, when I quickly checked Chrome, there were indeed canonical tags present (in both the static and rendered HTML).
Additionally, GSC reported thousands of URLs categorized as “duplicate without user-selected canonical.” That was just another sign that something was wrong… When I checked these URLs in Chrome with a mobile user agent and checked the rendered HTML, Canonicals were the case not is shown in the code. Additionally, the URL inspection tool did not report user-selected canonical URLs.
When I raised the issue with my customer, it turned out that they only published canonical tags for these URLs on desktop and not on mobile. And based on what I explained earlier about mobile-first indexing, Google will use the mobile version of the page for indexing purposes. So thousands of URLs had no canonical tags. And for larger and complex sites, you definitely want to make sure you’re sending the strongest possible signals about which URLs to index, what are the canonical URLs, etc. So, given the size and complexity of the site, this was an important insight.
My customer quickly resolved the issue and the correct Canonical tags are now published across all URLs on the site. That’s great, but the problem has been going on for a long time. This is another great example of how to ensure that the mobile versions of your URLs contain the correct content, structured data, instructions, canonical tags, and more.
Case 2: Thin pages *get thinner* on mobile.
The second case I will cover is a large website with a footprint of over 40 million URLs. It’s a complex site with many moving parts, which has also been impacted by major algorithm updates over time. As I dug into the audit, I noticed that the word count on some pages was lower than when viewed in Chrome.
So I quickly started checking the URLs on mobile and it was easy to see what was going on. The site published less core content on mobile than on desktop (and sometimes much less content). Checking the URLs in GSC and checking the crawl data confirmed this issue for many URLs on the site. The worst part was that this was the case already thinner pages that were even thinner when accessed via mobile devices. And as I explained, Google will use the mobile versions of the pages for indexing (so Google indexed less core content than the site owner thought).
My client is currently fixing this issue and the solution could result in much more content across millions of pages on the site. It goes without saying that you don’t want your already thin pages to become even thinner. From a quality perspective, this is not a good thing, especially on a large and complex website.
To check for mobile-first issues:
Again, this is just a PSA to ensure that website owners understand that it is important to ensure that all content, structured data, instructions, canonicals, etc. are present in the mobile versions of the pages. If not, you could be shooting yourself in the foot when it comes to SEO. Below I describe some ways to check your pages for problems.
URL Inspection Tool in Google Search Console (GSC):
This is the gold standard and a great way to check specific URLs in the GSC UI. Once you’ve verified a URL, you can check Google’s HTML indexedand then test it too Live URL to check the HTML code for the current version of the page. You can also use the URL Inspection API to inspect URLs in bulk for their indexing status, which may also uncover issues unique to mobile devices. Note that you won’t be able to see the HTML when checking via the API. This is only available through the GSC UI.
Crawling tools like Screaming Frog, Sitebulb and Lumar with JS rendering on:
Various crawling tools allow you to view the static and rendered HTML code in bulk and also view rendered screenshots. Additionally, you can crawl across mobile and desktop crawlers and then compare the crawls. Using crawling tools is scalable as you can crawl an entire site, a large portion of the site, etc. It’s worth noting that Lumar just added the ability to save the HTML code and rendered screenshots too. So all three of these crawling tools can be helpful on this front.
View static and rendered HTML in Lumar:
Comparison of crawls in Screaming Frog:
SEO Chrome Extensions:
Chrome extensions can provide a quick and easy way to review individual pages (one-time reviews). Sometimes you can spot problems by checking what appears in these extensions. For example this Detailed expansion allows you to easily view metadata, canonical tags, word count, headings, structured data and more. There are several great Chrome extensions and this is just one that I use all the time.
Chrome DevTools:
When you inspect a page in Chrome DevTools, you can see if the content is in the rendered HTML. And you can easily switch to mobile device emulation in DevTools to see the differences between mobile and desktop. You can then compare the rendered HTML between desktop and mobile. A quick tip: just press F12 on your keyboard to quickly check a URL, then press Ctrl-Shift-M to emulate the URL on a mobile device. Then select a mobile device from the list.
Site query + quoted text:
And finally, you can do a quick site query by using the page’s text in quotes. This will return pages containing this content from a specific website. Google’s John Mueller has long explained this technique as a quick way to check whether certain content has been indexed. Note that this is not helpful for checking metadata, statements like “noindex”, canonical tags, structured data, etc., but can help determine whether certain content is being indexed.
Summary: Don’t miss the mobile view.
Keep in mind that Google completed its transition to mobile-first indexing in fall 2023, meaning it will only use the mobile version of your pages for indexing. When auditing websites, make sure you view that site through a mobile lens to ensure all content, structured data, instructions, canonicals, and more are in place for indexing. If not, you could face strange SEO issues. The good news is that it’s pretty easy to spot the problems if you pay attention to the differences between mobile and desktop. I recommend using the tools I described in the second part of my post to check your pages (individually and in bulk). Good luck.
GG