Table of Contents
- Quick Answer
- History of Image Thumbnails in Google Search
- The Different Types of Image Thumbnails
- Qualifying Image Thumbnail Issues
- What My Research Shows
- Key Takeaways
When it comes to SEO, we want to ensure our clients get any competitive edge that’s available to them. One of the more engaging elements of Google’s search results is the ability for organic listings to stand out with SERP image thumbnails.
But not every site has access to the Google Search thumbnail treatment, specifically the multi-image treatment, which can have a significant impact on CTR. I’ve witnessed this situation time and time again, leaving SEO professionals scratching their heads.
My goal within this guide is to provide more clarity around the situation with actionable tips for troubleshooting image thumbnail issues. Before we get into my research, I’ll first provide some background on image thumbnails in Search for context.
When trying to get the multi-image thumbnail treatment showing for a web page, there are important steps to take in order to understand the situation. First of all, assess whether the page is experiencing preview issues or indexing issues, and whether it is a site-wide issue of page specific. My research has shown that both Structured Data or the website CMS shouldn’t impact the multi-image treatment. Instead, focus on factors that work such as image relevance, image quality, alt text, the product title, having >8 images on the page, sequence of appearance, along with ensuring the image background and product arrangement is in line with other sites that have the treatment.
History of Image Thumbnails in Google Search
Image thumbnails have been a feature of Google’s search results on mobile for quite some time now (several years at least). It was only after significant testing on desktop roughly a year ago, with a more recent launch, that image thumbnails became a standard feature of a large portion of Google’s search results.
And image thumbnails for organic listings aren’t a feature that are going away any time soon, with gradual increases in their prominence over time. According to Rank Ranger, image thumbnails appear in 40% of desktop SERPs and 65% of mobile SERPs.
Likewise, Advanced Web Ranking data suggests significant difference in prominence of the feature based on industry. With the top categories where image thumbnails are visible being in sectors such as Shopping, Style & Fashion, Food & Drink, and Travel.
Conversely, the categories where image thumbnails were less visible included Government, Politics, Personal Finance, and Education. Aren’t these just less visual sectors? Yes, which could be a big contributor to why image thumbnails appear less often.
Though my own research, which I’ll be getting into shortly, suggests that the multi-image format is almost exclusively in the eCommerce sector. With the single image format being more prevalent across a variety of industries.
The Different Types of Image Thumbnails
When it comes to Google SERP image thumbnails, there are effectively three different situations that can come about for a web page. Multiple images can show in a sequence, a single image can show as the preview, or no image at all.
Here’s a breakdown of what each looks like:
With the multi-image thumbnail treatment, this is where Google selects multiple images to appear within the search results preview. Here’s what this looks like:
Based on my research, I’ve seen Google pull as few as 4 images within the preview on desktop, which could be considered the minimum amount of images. That does however depend on the image orientation, with images in portrait requiring more images to fill out the space.
Single Image Thumbnails
Having thumbnails appearing with a single image for web pages is far more common than the multi-image treatment. For the data shown by tools such as Rank Ranger and AWR, it is the single treatment that is being logged. Here’s what this looks like:
Because of the prevalence of single image thumbnails, I haven’t seen much interest around how a single image is selected, so my research hasn’t focused too heavily around how single image thumbnails operate. SEOs are aware for the most part.
No Image Thumbnail(s)
Google also has the option to not show any image at all for search results, which tends to look like a standard web search listing. Here’s what this can look like:
SEO professionals are interested in getting a better understanding for why this treatment appears instead of the multi-image treatment on desktop in particular. Especially in situations where there looks to be relevant images on the page that could be extracted for use by Google as a thumbnail.
Now that we’ve covered the history of image thumbnails in Google Search and the different types of thumbnails that can appear, my post now moves on to the components that I know SEO experts will be interested in. First, I’ll give a breakdown for where to start when troubleshooting image thumbnail issues.
Qualifying Image Thumbnail Issues
Qualifying the extent of missing image thumbnails is the number one priority when troubleshooting issues. My experience with troubleshooting missing image thumbnails is that there are 3 levels of severity: ranking issues (level 1), preview issues (level 2), and indexing issues (level 3).
Each of the 3 levels of severity present their own problems. Within this section of my guide, I’ll be showing how to identify the level that your web page is operating on and what the level of severity means for your situation.
Level 1 Severity (Low): Ranking Issues
Update Sep 1st: as of recently, it looks like there is no longer a maximum amount of multi-image thumbnails that can appear for a page on Google. There was a period of testing where Google was showing more than 4 pages with multi-image thumbnails, and that has since started to show more often by default. With that in mind, I would say that there is no longer ‘Ranking Issues’ associated with trying to get the multi-image thumbnail treatment to appear.
Ranking issues are the most simple and the easiest to understand. My research (which I’ll get into more in a moment), has found that there is a multi-image thumbnail filter at play. I’ve discovered that Google will only ever show a maximum of 4 web pages with the multi-image treatment at once.
This is much like FAQ and How-to rich results, which have a filter that prevents more than 3 of each rich result showing at a time. With image thumbnails, the goal is to not have 4 multi-image treatments appearing above your page. This is assuming that your page qualifies for the multi-image treatment in the first place, which I’ll cover more within levels 2 and 3.
The example above does a good job of highlighting the impact of a rank-focused multi-image thumbnail disqualification. While the page on etsy.com ranks for the query “spice jars” in both Melbourne and Adelaide within Australia, the sequence of appearance of results on page 1 of Google is slightly different, which is common when location of the searcher changes.
It’s not the position of the Etsy URL that is the issue, but instead the fact that the page qualified for the top 4 multi-image thumbnail treatment on the left (in Melbourne). Whereas the results on the right (in Adelaide), the Etsy result did not qualify for the treatment because there were already 4 pages with the multi-image thumbnail treatment ranking above the page.
When reviewing the raw data sent to me by AWR for my article, I did find there to be a high concentration of image thumbnails for results that ranked in positions 1 and 2. There was still however an even spread for results in positions 3-10 and beyond. Although there are the most thumbnails that appear in position 2, I don’t believe there to be a special treatment for that ranking position. It is also important to note that the AWR data (along with Rank Ranger) covers thumbnails in general, not specifically the multi-image treatment.
That just about covers my research on severity level 1 (low) for the multi-image thumbnail treatment not showing for pages. There does not appear to be a filter similar to this that applies to the single thumbnail treatment. A total of 4 image thumbnails appearing on a SERP is just for the multi-image treatment, without any explicit factor coming into play which requires a page to rank in a specific position on the page to be able to qualify for the treatment.
Level 2 Severity (Medium): Preview Issues
If your web page is experiencing preview issues with respect to the multi-image treatment, this is where things start to become more complicated. The most effective way to figure out if your page has preview issues is to use a simple site search operator, testing out different queries that you rank for and are relevant to the page. For instance, here’s what this looks like for a page that isn’t experiencing a multi-image thumbnail preview issue:
In the example above, the page is showing correctly with the site search operator combined with a relevant query. This means that all the page needs to do is appear within the top 4 pages that qualify for the multi-image treatment, then there’s a high possibility that the treatment will appear for this page. Conversely, there are situations where images are being indexed (more on this in level 3), though are not appearing within the preview, posing a preview issue for the page.
Here’s an example of a page that is experiencing preview issues for a query that is relevant to the page and would ideally be showing the multi-image treatment:
As you can see, none of the images from the page populate within the snippet for the query within the site search operator. Images from the page are however shown below (related to Image Search) that look to be relevant to the query. This means the page is experiencing a preview issue. This then leads on to the worst case scenario: level 3.
Level 3 Severity (High): Indexing Issues
When a page is experiencing indexing issues with respect to image thumbnails, it can have a considerable impact on Google’s ability to surface images as a part of the web page snippet. Indexing issues for image thumbnail can either by page-level or site-wide. Site-wide means the issues are far more widespread and requires review of the approach as a whole.
When assessing indexing issues, we will again use the same approach used within level 2 related to the site search operator. The difference between levels 2 and 3 relate to images not appearing within Image Search, hinting that there’s an issue with Google accessing the image content in the first place. As an example, Foot Locker have a page on their site that receives a reasonable amount of traffic (~11K p/mo organic visits based on Ahrefs data), but none of the images on the category page are indexed:
The above shows the site search operator without a query included, but the same result happens for when various relevant queries are included in the mix. This is not a good sign for the web page with respect to image thumbnails, with Google not even having the chance to even select imagery for the single thumbnail format let alone the multi-image treatment.
If your web page falls into this category, you will then need to figure out whether the issue is page-based or sitewide. If it’s page-based, then it relates to the content specifically on that URL. If it’s sitewide, then you’ve got a bigger problem on your hands and likely relates to an approach being used across the site that Google isn’t reacting well to.
An easy simple way to figure out whether your site is experiencing site-wide image thumbnail issues can be assessed by setting your search settings to 100 pages at a time (instead of 10) and using a site search operator with various queries the site ranks for. If say the top 10 queries don’t yield a single image thumbnail, and that was the expected result, you may have a site-wide image thumbnail indexing issue. For example, Kmart is one site in Australia that is experiencing site-wide thumbnail issues.
For Kmart, they have very few single thumbnails appearing for category pages through their site despite those pages having a considerable number of relevant visuals. Going an additional layer for image thumbnail indexing issues, Kmart doesn’t rank for any multi-image thumbnail snippets at all from what I can see. I would consider Kmart to be a prime example of a site that is being hindered by level 3 image thumbnail issues.
Establishing each of the levels of severity covered within this section of my post has the goal of figuring out how close you are to target to achieving the multi-image thumbnail treatment. By following the approach I’ve highlighted within this section of my post you will at least have an idea of how impactful and widespread the issues are that your site is experiencing.
What My Research Shows
My research for image thumbnails focused heavily around the multi-image treatment that many SEO professionals are interested in. In particular, I’ve found there to be a lot of discussion around the impact of Structured Data and the CMS used by sites that could influence the way the multi-image thumbnail treatment appears on desktop. To be clear, I found no correlation among either Structured Data or a website’s CMS being a core factor to why or why not a snippet appears with the multi-image treatment.
Structured Data and Multi-Image Thumbnails
With respect to Structured Data (or as Schema Markup as some refer to it as), I found that roughly 30% of all results in my research that had the multi-image treatment had no Structured Data at all on the page (vast majority being eCommerce category pages). There was however a small portion which did have ItemList Schema (another that some suggest helps with the multi-image treatment), though this markup has every single product that appears within a category for the most part. So it’s effectively impossible to be sure that the Schema is the influential factor, when a selection of images are selected to appear as a snippet. For that reason, I don’t have much confidence in ItemList as a factor, or other Schema’s for that matter, unless a test displayed a before and after correlation.
Continuing on with the theory of Schema being influential to the multi-image treatment, I also often see confusion around the term “rich result” in SEO. Many consider a “rich result” to be anything that looks different to a standard web page snippet, and that’s even how Google defines it. It’s my opinion that this phrasing has been taken out of context, which leads to a lot of confusion in my experience. A “rich result” is something that stems from Structured Data, not HTML, and should be referenced within the Search Gallery to qualify for categorisation in that way. So because a treatment specific to image thumbnails (in particular multi-image thumbnails) doesn’t appear within the Search Gallery, and has no evidence suggesting it stems from Structured Data, we shouldn’t categorise it in that way.
I will however add that I have seen the single thumbnail treatment be impacted by Structured Data use. This is in instances where there aren’t many relevant images on a page that are accessible to Google, so Google then falls back on an image that is part of the markup on the page, but not found on the HTML of the page itself. So like I said, I’m not counting it out as a contributing factor that can be considered for inclusion in thumbnails, but I just don’t have enough evidence to say that it is an effective method to receive the multi-image treatment.
Content Management System (CMS) and Multi-Image Thumbnails
On the topic of the impact of Content Management System (CMS) impacting the multi-image thumbnail treatment, I found no evidence to suggest that a specific CMS in itself was to blame. Instead, more likely the additional features that are employed on category pages across various platforms. When I mentioned that I would be conducting this research and writing about it, I had several people mention that they thought Shopify wasn’t a good CMS for generating multi-image thumbnails. I have found this to be inconclusive, with sites that were built with Shopify showing the multi-image treatment both correctly and incorrectly.
It is however worth noting that I found that a high number of sites using the Magento CMS have good coverage with the multi-image treatment. This isn’t to say that Magento is definitively better than other CMSs for receiving the treatment, but there does seem to be good coverage for these sites within my research sample. The same could be said about WordPress but to a lesser extent.
Influential factors on image thumbnails
To be clear, there weren’t a lot of consistencies with the findings from my research. It wasn’t as if a site did X they then had great exposure to the multi-image thumbnail treatment, or if they were doing Y that they didn’t receive any exposure. My experience was that there could be other factors at play that can bypass something foundational, such as having alt text added to images. There were however some commonalities among sites that did well with the multi-image treatment that I’d like to list.
The goal of this list is to provide a checklist of sorts for when troubleshooting the multi-image thumbnail treatment not appearing for your site. Going back to the levels of severity covered earlier in my post, this section is focused exclusively on levels 2-3, which focus around the previews showing effectively for your page and indexing the image content in general. Here’s some ideas to test out if your page or site falls into either one of these categories.
- Image relevance: to be considered for the SERP preview (level 2), there is an assumption that most of the imagery on the page is indexed. This then makes image relevance a more significant factor, as Google will be relying more heavily on the image being appropriate to show in search results as a part of the snippet for the page. Ensure that the images are relevant to the query by comparing to pages on other sites with the multi-image treatment as a benchmark.
- Image quality: I’ve seen cases where the size of the image was causing quality issues, which could likely be the reason for why Google wasn’t including it in the snippet. The quality of images are already reduced when rendered in Google’s search results, so if the image is already low quality then it could result in Google not wanting to present it in their search results at all. Ensure images are of reasonable sizing and aren’t pixelated.
- Alt text: this could be considered one of the most basic and foundational aspects of Image SEO, but is still one where I’ve come across category pages where the images don’t have alt text. Again, this isn’t a dealbreaker from what I’ve seen, but it’s one that you’ll want to check off your list early on when trying to troubleshoot image thumbnail issues.
- Product title: the product titles that appear on category pages provide an opportunity to optimise for queries that the category ranks for. It also allows the page an opportunity to provide more context to specific images, which can be a consideration for assisting with surfacing the image in SERPs.
- >8 relevant images: this is one where there is no specific amount of images which are perfect, as it relates more so to orientation, but having more than 8 images on the page that qualify for the multi-image thumbnail treatment is important. If there were 4 images for instance but they were all in portrait, that may not be enough to fill out the search results snippet on desktop, resulting in the snippet resorting to only the single thumbnail treatment.
- Sequence of appearance: having your best and most relevant images for extraction higher on the page could be a factor at play. If the page were to have several images that weren’t relevant enough to the page content (I’ve seen this happen for gift idea pages), then you could lose your opportunity to receive the multi-image treatment.
- Transparent backgrounds: when there is too much transparent space on a product image, I’ve seen this result in the background becoming black (instead of white) in Google’s search results. I’ve seen this happen for single thumbnails, but not for the multi-image treatment. This could be because Google doesn’t want to display multiple images with black backgrounds (which generally don’t contrast well) in search results.
- NEW (Product arrangement): with one large-scale eCommerce site I work with, they weren’t receiving the multi-image treatment for core category pages because product images featured various products within the image (ex: several pairs of shoes with different colours), instead of just a single product, which Google seems to prefer. Ensure that the image inclusions aren’t too cluttered for Google to easily extract several images and display them alongside one another in an arrangement.
The 9 suggestions above provide a good starting point for figuring out some of the more common issues I’ve encountered in my research. I’m also currently working with a large eCommerce site in Australia who is testing out some of the suggestions I’ve detailed above. I’ll be documenting this to discover which suggestion eventually allowed them to receive the multi-image treatment, so stay tuned.
When it comes to Google SERP image thumbnails, there is a lot to unpack with respect to receiving the multi-image treatment. The first step in assessing impact should be by understanding the severity of the situation, spanning from a page having a ranking issue all the way down to significant and widespread indexing issues.
Once the situation that your site fits into is established, it’s time to start putting image thumbnail-related theories to work. As detailed within my research, I don’t believe Structured Data will have a direct impact on the multi-image thumbnail treatment, but could assist with the single treatment if that’s the next best source for Google. Putting blame on the CMS is also unlikely to be helpful, as there’s not much evidence to suggest the CMS on its own is the cause.
There are however 9 different ideas that I would suggest looking into. Starting out with disabling JS to see if images load, which could easily be a contributor to level 3 (indexing issues). Other recommendations include assessing image quality and relevance, adding alt text, reviewing product titles, the number of images on the page, their sequence of appearance, and what the background of images looks like. Assessing each is a good starting point in troubleshooting the multi-image treatment.
As mentioned earlier in my post, I’m currently putting my own research into practice with a large-scale eCommerce site within Australia that’s a client of mine. I’ll then update my post with more certainty around the recommendation that worked for my client. With that said, I welcome feedback on my list of ideas for troubleshooting the multi-image thumbnail treatment. Have a recommendation that’s worked for you that’s not in the list? Feel free to let me know on Twitter and I’ll credit you within my guide.
FAQs for Image Thumbnails
Is Structured Data a requirement to receive the multi-image thumbnail treatment?
No. Structured Data is not a requirement to receive image thumbnails in Google’s search results in general. Pages without Schema are able to generate the multi-image treatment, which means it’s not a requirement. That doesn’t mean Schema doesn’t help at all. I just don’t have enough evidence to recommend it as an approach for troubleshooting the issue.
Can an image thumbnail be populated on a page from a completely different URL on that site or another site?
No. The thumbnail that appears in Google’s search results is from an image that is located within the source code for that page, not a different page or website. If the thumbnail is appearing for your page, it means that it’s somewhere in there, you just might need to do some digging in DevTools or within the rendered HTML by using Google’s Rich Results Test.
Do indented results have the ability to show the multi-image treatment?
No. Indented results (that often appear as the 2nd result for a website) don’t appear to have the ability to yield the multi-image treatment. It looks like only the first URL will have the full treatment. The same goes for FAQ rich results. If a page has an indented URL appearing along with the initial URL and they are both eligible for FAQ rich results, only the initial URL will appear with the FAQ treatment.
Can pages that yield an FAQ Schema rich result show the multi-image treatment?
Yes. It looks like this is possible based on my research. If a page qualifies for both FAQ rich results and also the multi-image thumbnail treatment, both can appear for the page on desktop at the same time. Here’s what this can look like:
Does Shopify or other Content Management Systems negatively impact the multi-image treatment?
No. I’m not seeing a connection with a specific CMS and exclusion from the multi-image treatment with thumbnails. It does seem like some platforms (like Shopify) do sometimes use JS to show images on category pages however, which could certainly be a contributor to image thumbnail issues.
Does the og:image tag influence the multi-image thumbnail treatment?
Because the og:image tag only specifies a single image, it’s not an approach that would have an impact on whether Google shows multiple images for a page or not. This is because Google needs access to a selection of images (my recommendation is at least 8) in order to show multiple images in SERPs. Having an og:image tag may help with the single image thumbnail treatment, but not for multiple images.