Canonical Tag on Mobile Site?

posted December 10th, 2010

The title of this post is actually a query that I see frequently on this blog, and I’m a bit disheartened that so many people are still confused about this issue. Wanted to quickly clarify to help those people who are wondering whether they should use the rel=canonical tag on their mobile sites. The short answer is an emphatic “no”, you shouldn’t use a canonical tag on your mobile sites; but if you want more information on the topic, keep reading.

The issue as I understand it is, site owners are creating mobile-formatted versions of their desktop sites, and because there’s no content on these sites that isn’t on their desktop sites, they don’t want to hurt their desktop web site’s ability to rank on competitive keywords by diluting the link equity to the page. It’s a legitimate concern, but it’s a bit paranoid, as in reality mobile sites are not treated like duplicate content.

In fact, if you assume that they are duplicate content, and remove them from the search results with robots.txt or the canonical tag, you make it very difficult for people to find your mobile site if they’re looking for it.

Take Toys R Us, for example. Their mobile site is currently powered by Digby, who nofollows their mobile sites with robots.txt. This, like the canonical tag, effectively makes them invisible in search results. For example, if you search for [toys r us mobile site] hoping to find a site that works on your phone, you get a paid search ad, followed by 2 listings for the Toys R Us locations in Mobile, Alabama, followed by the Toys R Us desktop site with a page talking about the Toys R Us mobile content, which includes a mobile site.



If you can read the tiny text on this page, you might click through and be redirected to the mobile site at, but you’ll probably have to magnify the page in order to understand that is an option.


So for this particular query, which is not only a brand-loyal query but a navigational query, it would require the user to either click through on the paid listing, or scroll down, click through, magnify their screen and click through to find what they’re looking for. For the organic results, that’s asking a searcher to type in a query and do 4 additional steps before they’re able to find what they’re looking for, when they had already put in a very specific navigational query in hopes of getting to this site more quickly.

If you think that this is a user experience that Google will reward with long-term rankings, you may have become an SEO yesterday.

When you consider queries that are not brand-loyal queries, the situation becomes even more dire. Keeping with the Toys R Us example, let’s assume that I know my son likes Thomas the Train and I want to get him a Thomas the Train toy for Christmas, but I don’t know what’s out there or where to buy, so I do some research in a cab on the way to a meeting downtown. When I put in [thomas toys] in Google (which is one of the top toy related queries in the past 90 days, so Toys R Us should have optimized content for it even though it’s not a brand-loyal query) on my Android phone, I get a result page that shows two paid ads and one natural listing above the fold.


Fortunately for Toys R Us, they are accounting for mobile searches with the paid ad, but since mobile SEO is about the natural results, this is not optimization.

If in my taxicab search session I decide to scroll down to the fifth organic result on my mobile phone, I will find a relevant page on the Toys R Us desktop site. But since the only page that appears to redirect for mobile users is the root domain, it will not redirect me looking for results in a cab on my way to a meeting.


Because I have a limited amount of time to do research, it’s very likely that I will not spend a lot of time pinching and zooming on my smartphone to find the information that I’m looking for, and Toys R Us would have wasted an opportunity to convert a user who might have otherwise purchased a Thomas the Train toy either on my way home for the meeting or right there in the cab.

Consider a hypothetical contrary example as an illustration for what should be meant for mobile search engine optimization: Toys R Us doesn’t nofollow their mobile site with robots.txt, but instead optimizes their mobile site for the mobile user experience. They do query analysis to better understand the mobile user experience and find that their audience includes people like me who are frustrated at their mobile search experience. They take time to properly index the site and ensure that it is returned for relevant queries by creating a mobile search-optimized information architecture that meets the needs of the mobile searcher. Once all that’s done, they make it possible for the site to meet the user’s goals with as little hassle as possible by allowing one click conversions and local store directions and hours. They get more qualified traffic from search results because they would have, in this scenario, a more optimized site.

Unfortunately, they simply made their desktop site usable in mobile in certain scenarios (not search), and made the mobile version invisible in mobile search. If you consider this optimization, please continue to use the robots.txt file or canonical tag on your mobile site and call it what you want. Just hope your competitors don’t actually do some optimization of their mobile content and displace you even more in the natural search results.

Also, no disrespect to my friends at Toys R Us or Digby. I used them as an example, but I could use many others in their place. Please consider this free advice about the value of optimizing mobile sites instead of burying them.

Listing some good resources below about how to properly show content to mobile users and desktop users. And if you do represent a brand that wants to be competitive in mobile, but you don’t want to go it alone, there are a few agencies out there who can help you do it successfully, including my employer, Resolution Media.

Resources about alternatives to using rel=canonical on mobile sites

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8 Responses to “Canonical Tag on Mobile Site?”

  1. [...] impressions for smartphones than for feature phones. One keyword ([thomas the tank engine toys], oddly) had 42x the amount of searches on smartphones that it had on feature phones. If someone who sold [...]

  2. Peter says:


    What if Toys R Us blocked only desktop Googlebot in its robots.txt file (instead of current “*” wildcard). Wouldn’t this be the best option?

  3. Peter, no I don’t believe that would change their situation very much at all, actually. It would be better than blocking the mobile site entirely, in that the site would still be in the mobile index, but it still wouldn’t be optimized in the sense that it would have any chance at all of being competitive for queries from mobile devices. The transcoded Digby site would have to be optimized in order to compete, and just making the site eligible to be returned doesn’t mean that it will be. Still many issues to overcome before it’s competitive. Thanks for the question.

  4. Peter says:

    It makes sense. As long as it’s clear it’s a mobile site (mobile keywords in titles etc., mobile sitemap, shorter URLs, “lighter” code etc.) search engines should get it right.

    I’m doing some research and I can see how many different recommendations you can find (even from mobile seo experts and search engines).


  5. Joel says:

    The best article on this comes straight from Google.

    My company recently had a mobile site developed externally and they canonicalized the entire site. It’s not the right way to do it according to the Google Blog and I will change it post holiday season, but I don’t think it really hurts you either. For example, we only redirect Android/iPhone users who get the same search results as a desktop user (as far as I can tell in my test searches).

  6. Thanks, Joel. That process is also in the Google SEO Starter Guide that I mentioned. Redirecting content based on user agent is definitely an option, and it’s not considered cloaking, but I would hardly call it optimization. To be honest, I don’t think Google’s really figured out how to return quality mobile content for mobile queries, or their results would contain a lot fewer instances of the pages that require a user to do three or four extra steps before they get the information that they’re looking for. The results are getting better, but given Google’s modus operandi is to provide a great user experience and get instant answers when they’re needed, they still have a long way to go.

    As for the smartphone results being the same as desktop results, I know they can often seem that way in one-off searches, but if you look at ranking data in bulk I think you might be surprised to see the subtle differences. For example, I looked at 54 similar queries in a client’s most competitive category recently and found that 36 of the queries had a higher average ranking in the desktop results, 17 were ranked higher in the mobile results, and only 1 of the 54 queries had the same ranking on the desktop that it did in the smartphone results.

    That being said, I think you’re wise to remove the canonical tag from the mobile site, and optimize the content that you will be redirecting smartphone users to. Not only will it not hurt you from an SEO perspective, but it will probably help you both in terms of increased traffic and conversions. Thanks for the comments.

  7. Yes, there are quite a few disparate recommendations out there, unfortunately. Very similar to when we first started optimizing desktop sites, for those of us who are old enough to remember that confusion. As more people like you start asking questions about mobile SEO, the engines and experts will eventually start agreeing; but unfortunately not a lot of attention is paid to the topic relative to desktop search. Given how fast mobile search is and has been growing, I think people will have to start discussing these topics more if they’re going to be able to do their jobs well. This is a good start, though. :)

  8. [...] the same time, if you don’t have at least a page on your site optimized for mobile users, you will not be visible for high-converting brand-loyal navigational queries (e.g. [toys r us mobile..., and your bounce rate from search results will be high, while your conversion rate remains low. As [...]