Rel=Canonical Tag: How to Optimize Link Rel=”Canonical” For SEO

By | August 10, 2019

Today, we’re going to talk about canonical
URLs or the fabled rel canonical tag. We are going deep into the nerd woods on this
one, folks, so buckle up. We’re going to talk about what good canonicalization
looks like, how this can really mess up your website if you get it wrong. If you get it right, you can clean up a lot
of really bad duplicate content and fix a ton of technical behind the scenes problem. Stay for the whole video because we’re going
to talk about every possible edge case as well. I’m Tommy Griffith with Let’s get going. Okay. So canonical URLs or the rel canonical tags,
so we’re going to dive into this. We’re going to go pretty heavy into the technical
weeds here. Just a quick reminder before we do that. Canonical tags are part of SEO and SEO is
just one piece of digital marketing. This is one channel and so keep that in mind
as we do this. We’re zoning in on one particular channel
of what should be a much larger, more comprehensive digital marketing strategy. Just keep that at top of mind as we talk about
this. Then within SEO, canonical URLs or the rel
canonical tag is just one tiny component of a much larger piece of this entire puzzle. Canonical URLs, it’s really just a fancy,
overly technical word for saying, “This is how we deal with duplicates.” The rel canonical tag that we use on our webpages
tell search engines where the original version of a page lives. It’s effectively pointing to the master copy
of a page. Modern web applications create this massive
problem for us where we have lots and lots and lots of the different versions of the
same thing. If we weren’t doing this, if we weren’t handling
this, it would be a massive problem for the internet and for any search engine to handle. A canonical tag on a webpage tells a search
engine which version of the page that you want ranking, and so this is really, really
vital for eCommerce sites and for any modern web application that has a sorting problem. I used to manage search engine optimization
at Airbnb and this was a massive problem for us. If you have a list of a thousand homes in
a particular city and you have lots of different filters, there’s lots of different ways to
organize and arrange that page. Sure, you have a thousand homes but some of
them are the entire home. Some of them are shared. Some of them are two bedrooms, four bedrooms,
eight bedrooms. Some of them have a pool. Some of them are family friendly. Some of them have a sauna. Some of them are instant book. Every time you add an additional layer of
filtering, you’re essentially rendering a new different type of page on the same dataset,
the same thousand listings. If you do this ad nauseam for as many possible
filters as you can think of, you essentially get infinite pages and that becomes a giant
mess for any search engine to deal with. The basic idea here is we’re saying, okay,
we still want our users to be able to filter. We still want our users to be able to render
the page in different ways, but we want to tell the search engine, “Hey, Google. I know it looks like we have a thousand pages
but really we only have one.” That’s what the canonical URL is. It’s a very specific suggestion to search
engines to say, “This is the master copy of the URL. Only put this one in search results and ignore
the rest.” A couple of other things on canonical URLs
and a good way to think about this. Duplicate content is bad. Duplicate content can hurt your crawl budget
so Google and other search engines allocate a certain number of request per day or per
week or per month and if they’re spending all that time crawling what to garbage that
you don’t want them to crawl, that’s hurtful to you. That’s not good for you as a web master. Duplicate content can lower rankings. If Google is seeing a pattern of duplication
on your site over and over and over again, that can drop you in the rankings. Obviously that’s not good. Duplicate content can also send users to really
low quality pages. Let’s say you don’t care about crawl budget. Let’s say duplicate content isn’t hurting
your rankings yet. If users are finding your unnecessary garbage
in search results, that’s bad. That’s not good at all. Do keep that in mind. These are all reasons why you want to solve
the duplicate content problem because it’s not good for search engines, it’s not good
for you and your rankings and it’s not good for your users either. That’s why duplicate content is bad. Let’s look at some examples here. Let’s say we are and we have a page
on our website called men’s shoes and we want it ranking number one in Google for the term
“men’s shoes.” On, this is the original
version of the page and we would implement a canonical tag here, link rel=”canonical”
and the href is This is called a self-referential canonical
tag. The original master copy of the page is pointing
to itself and that’s fine. We can go ahead and do that. There’s no problem at all. We are self-canonicalizing here. No issues at all and that’s totally fine. This is the master copy. The canonical tag is pointing to itself. This is a fine suggestion for Google. Let’s look at that same page with a filter
on it. Let’s say we go to and
we want to sort this page by everything that’s size 10, and so we add a filter. Maybe a URL parameter gets added to the URL. It’s ?size=10. We now have a new page that has a new filter
on it, but we don’t want that page in search results, so the canonical tag stays the same. We have this page. It exists for users but if Google were to
ever find it, it sees that canonical tag in the head and we’re here saying, “You’re on
this page, but actually don’t index it. Please index this other one, the master copy,
and any links that this page gets, can you go ahead and pass that over to the master
copy? We don’t want to index this.” This would be an example where there isn’t
any searcher intent for this particular type of phrase. We didn’t want this page ranking. There wasn’t any search volume for it and
so we were pointing it back to the master copy. If there’s search volume for Nike shoe size
10, maybe we would leave this alone and self-canonicalize. Maybe we would want it in the search results. But in this particular case, let’s say that
for all intents and purposes of this example, we don’t want it in search results so we’re
going to add a canonical tag back to the master copy. All right. Well, I had one more filter, Now we’re looking at all the Nike men’s shoes
that are size 10 and color red. It’s the same thing. It’s another page. It’s a different set of filtering. It’s more specific but we don’t want this
page in the index. We’re going to keep the canonical tag back
on the master copy as this URL sort of gets more and more parameters on it, we’re still
pointing back to the master copy. Link rel=”canonical”, href, Let’s add another parameter, another filter,, size=10&color=red&sale=yes. Again, we don’t want this in the index so
we’re going to go ahead and canonicalize back to the master copy. Cool. In every one of those situations, we had essentially
[inaudible 00:07:19] search like filtering that which is too lengthy and not necessary,
not useful to users coming in from search engines. Just too many pages so we wanted to kill all
of them. We want to kill all those pages so we would
canonicalize those URLs up to the master copy. However, let’s look at a different situation
here. It’s the same URL however there’s a certain
type of filtering that’s really important to us. In this case, it’s Jordans. Nike’s Jordan shoe. Let’s say we are doing a promotion on the
homepage and there’s 25,000 people a month searching for Nike men’s Jordan shoes, and
we want this page in the index. We would self-canonicalize this URL. Same URL, This is a different type of filtering. In this particular case, we would not canonicalize
back up to the master copy. We would self-canonicalize. What we’re doing here is when Google gets
this URL, Google is saying, “Hey.” We’re saying to Google, “Hey, actually this
page is the master copy. Please put it in your index.” In this particular situation, the page is
in important to us. It’s a unique and good experience for users. It has search volume behind it. We would self-canonicalize and essentially
create a new page. You do want to watch out and make sure that
it’s not a complete duplicate of the original men’s shoes page. Make sure there’s some differentiation there
for sure. This would be one way to capture a bunch of
search volume that you may not be capturing if you were to self-canonicalize back up to
the core page because you’re not able to get it into the index if you do that. The way to think about the rel canonical tag
and canonicalization in general is what would search results look like if Google didn’t
have a way to remove duplicate content? Next time you’re on an eCommerce site, every
time you click anything, watch the URL bar. It is a massive, massive, massive problem. The point here is that the internet would
suck without this. It’s really good that Google has built in
the technical way to handle a lot of this. We have a ton of URLs here that are effectively
all the same thing, mens-shoes, mens-shoes, size=10, size=10&color is red. Think about every possible permutation of
this. It can start to get really messy really, really
quick. The internet would be terrible if we could
not handle this. This is one way to handle duplicate content. It makes it easier for both search engines
and for users. A couple more tips on rel canonical and canonical
URLs. Self-referential canonical tags are fine. There’s some debate out there at a really
high technical levels with massive web applications. Some people like to not do self-referential
canonical tags. TripAdvisor is doing some really interesting
stuff on this. Take a look at their source code and see what
they are doing. I’ve seen evidence for and against this. It really depends on your situation. If you’re just getting into this, self-referential
canonical tags are fine. Canonicalize your homepage. Homepages I find are one of the most oddly
linked to thing. There’s the http version. There’s https. There’s http://www. There’s https://www. There’s, /index.html. There’s a ton of different ways to render
homepages. People mess it up all the time. Canonicalizing your homepage to the core one,
picking the core one and then canonicalizing every other variation around that is really
helpful, so I highly recommend you do that. Canonical tags are a suggestion, not a directive. Robots.txt is generally a directive. 301 redirects are generally a directive. You’re telling a search engine, “Hey, you
have to do this.” Canonical tags are a suggestion. Google has put out a lot of information on
this. Their point here is that web masters mess
this up a lot. Web masters mess up a lot of stuff a lot and
so this is one of those situations where they actively admit that they’re allowed to ignore
you if they think you’re shooting yourself in the foot. Canonical tags are one additional suggestion
that we give to search engines to advise them on how to handle your duplicate content. A lot of people say, “Hey, I put a canonical
tag and it’s not working. What happened?” Take a look a little more deeply at what you
have going on because Google may be getting mixed signals from you which we’ll talk about
next. But the basic idea here is like they’re not
taking full responsibility for this tag as a directive. They’re not saying that they will absolutely
enforce it. But more often than not, I see that they do. Cross-domain canonicalization is okay. One example of this might be let’s say your
publishing site … You have 20 different websites and every time you write a new blog
post, it cascades across all 20 of your domains. It is totally fine if you write a blog post
for It is totally fine to post that on website2
and website3 and and cross-domain canonicalize back to the original. Anything that does cross canonicalize won’t
show up in the index. You’re essentially saying, “Hey, Google, don’t
put this in the index. The original version is over here.” However, any links that you get on any of
those pages should be attributed back to the original master copy. Cross-domain canonicalization is totally fine
so feel free to do that if you want. Don’t send mixed signals. There’s a lot of ways to mess this up. Taking two pages and canonicalizing them to
each other, taking two pages, canonicalizing one to one and 301 redirecting one to the
other, there’s a lot of different ways to mess this up. Don’t send mixed signals. Figure out what your plan is. Figure out what you want your master copy
to be and hammer that plan. Make sure it’s very, very clear in every element. The other thing to think about 301 redirects
versus canonical tags, a lot of people say, “Okay. Essentially I want to kill a bunch of duplicate
pages. I want to consolidate them all into one page. Should I use a canonical tag or a 301 redirect?” The general consensus is this. First of all, 301 redirect seem to be a stronger
signal in terms of link equity. If you have two deprecated pages, you want
to kill them, you want to pass all those links over to a different page, it feels like most
people see that 301 redirects are generally more helpful in that sense. You generally seem to get more link equity
when you do a 301 redirect. Do keep that in mind. The other thing to think about is that the
experience for the user is different with a canonical tag. With a 301 redirect, the user moves to the
new end page. With a canonical tag, they do not. You’re saying to Google, “Hey, Google. The page you’re on is a copy. Ignore it and send any links over to this
other page.” But the user is still staying there so keep
that in mind. The first thing people think of is they think
about manipulation. They say, “Okay. Well, then all I have to do is get a bunch
of links to a page and then canonicalize it to a completely unrelated page. Then I can rank super high and win the internet.” It doesn’t work that way. It looks like what Google is doing is finding
a document relevancy piece to this. They want to make sure that it’s an actual
copy. If the page you’re canonicalizing to is dramatically
different than the one that you’re currently on, it’s going to be ignored. If you have a page about blue widgets and
you’re canonicalizing to a page about gorillas, it’s not going to work is the basic point
there so do keep that in mind when you think about 301 redirects versus canonical tags. That’s it. That’s really all there is to canonical URLs
and the rel canonical tag. I hope that was useful. If it was helpful and if you learned something
today, go ahead and click “subscribe” down below for even more digital marketing tactics
and tips from us. If you’re on YouTube, I would love a comment. What do you think? Is this how you implement rel canonical tags? Have you seen it done differently? I’d love to hear from you. I read every single one. Finally, if you want even more from us with
a super comprehensive SEO checklist, there’s a free downloadable. Go ahead and click that link down below to to get a free comprehensive technical SEO checklist right now. Thanks a lot.

10 thoughts on “Rel=Canonical Tag: How to Optimize Link Rel=”Canonical” For SEO

  1. Two Views Post author

    Great instruction and explanation. We are trying this for our site The only thing we wondered about is using http or https in the code and will old non-encrypted pages be sent or indexed to the https version in the canonical tag?

  2. Feng Shui Meister Post author

    how can I remove the canonical tag in WordPress, if douplicates are removed?

  3. Benjamin Kaleblevi Post author

    I think you are very good at communicating. I went to other sites on the subject but found this information a lot easier to digest. Thank You.

  4. Jack Shocklee Post author

    Hey Tommy, you do a great job teaching. Could you explain the steps I would take to canonicalize my home page?

  5. Backdesk Innovative Solutions Post author

    I activated the canonical tag on my category and it shows /category/beauty-shops-abuja/ . I'll like to find out if this is corrected and makes my page shown on search engine?

  6. Royal Quality Logistics Post author

    This is a great video, but the title should read an explanation of Canonical SEO. I thought it was a technical video on how to place it on our website. Just a suggestion

  7. art21 seo Post author

    Thanks bro for sharing this knowledge. Great video!

  8. ExtraNullByte Post author

    Quick question on this, what happens when someone googles "red size 10 men shoes" or "<insert shoes name> men shoes", if page is not indexed and google is unaware of those shoes existing on your website, where would you rank?


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