So first off, what we're trying to say is this URL is the one that we want Google and the other search engines to index and to rank. These other URLs that potentially have similar content or that are serving a similar purpose or perhaps are exact duplicates, but, for some reason, we have additional URLs of them, those ones should all tell the search engines, "No, no, this guy over here is the one you want." You'll see URLs that are not the original version, that have some weird URL parameter ranking in Google sometimes. I should canonicalize all of my ranking signals, and I should make sure that this other version ranks." That way, in the event that someone you've never even met decides to plug in question mark, some weird parameter and point that to you, you're still telling Google, "Hey, guess what? Then you can basically tell Google, through the Search Parameters section, to make certain kinds of parameters passive. When to canonicalize URLs Last but not least, when should we canonicalize URLs versus not? If you want to maintain that old version, but you'd like the old version's ranking signals to come to the new version, you can take the content from the old version, republish that at /a-old. Then take /a and redirect that or publish the new version on there and have that version be the one that is canonical and the old version exist at some URL you've just created but that's /old. If you have content that is expiring, a piece of content, a product, an event, something like that that's going away, it's no longer available and there's a next best version, the version that you think is most likely to solve the searcher's problems and that they're probably looking for anyway, you can canonicalize in that case, usually with a 301 rather than with a rel=canonical, because you don't want someone visiting the old page where nothing is available.
If you’ve ever had any questions about the canonical tag, well, have we got the Whiteboard Friday for you. In today’s episode, Rand defines what rel=canonical means and its intended purpose, when it’s recommended you use it, how to use it, and sticky situations to avoid.
Click on the whiteboard image above to open a high-resolution version in a new tab!
Video Transcription
Howdy, Moz fans, and welcome to another edition of Whiteboard Friday. This week, we’re going to chat about some SEO best practices for canonicalization and use of the rel=canonical tag.
Before we do that, I think it pays to talk about what a canonical URL is, because a canonical URL doesn’t just refer to a page upon which we are targeting or using the rel=canonical tag. Canonicalization has been around, in fact, much longer than the rel=canonical tag itself, which came out in 2009, and there are a bunch of different things that a canonical URL means.
What is a “canonical” URL?
So first off, what we’re trying to say is this URL is the one that we want Google and the other search engines to index and to rank. These other URLs that potentially have similar content or that are serving a similar purpose or perhaps are exact duplicates, but, for some reason, we have additional URLs of them, those ones should all tell the search engines, “No, no, this guy over here is the one you want.”
So, for example, I’ve got a canonical URL, ABC.com/a.
Then I have a duplicate of that for some reason. Maybe it’s a historical artifact or a problem in my site architecture. Maybe I intentionally did it. Maybe I’m doing it for some sort of tracking or testing purposes. But that URL is at ABC.com/b.
Then I have this other version, ABC.com/a?ref=twitter. What’s going on there? Well, that’s a URL parameter. The URL parameter doesn’t change the content. The content is exactly the same as A, but I really don’t want Google to get confused and rank this version, which can happen by the way. You’ll see URLs that are not the original version, that have some weird URL parameter ranking in Google sometimes. Sometimes this version gets more links than this version because they’re shared on Twitter, and so that’s the one everybody picked up and copied and pasted and linked to. That’s all fine and well, so long as we canonicalize it.
Or this one, it’s a print version. It’s ABC.com/aprint.html. So, in all of these cases, what I want to do is I want to tell Google, “Don’t index this one. Index this one. Don’t index this one. Index this one. Don’t index this one. Index this one.”
I can do that using this, the link rel=canonical, the href telling Google, “This is the page.” You put this in the header tag of any document and Google will know, “Aha, this is a copy or a clone or a duplicate of this other one. I should canonicalize all of my ranking signals, and I should make sure that this other version ranks.”
By the way, you can be self-referential. So it is perfectly fine for ABC.com/a to go ahead and use this as well, pointing to itself. That way, in the event that someone you’ve never even met decides to plug in question mark, some weird parameter and point that to you, you’re still telling Google, “Hey, guess what? This is the original version.”
Great. So since I don’t want Google to be confused, I can use this canonicalization process to do it. The rel=canonical tag is a great way to go. By the way, FYI, it can be used cross-domain. So, for example, if I republish the content on A at something like a Medium.com/@RandFish, which is, I think, my Medium account, /a, guess what? I can put in a cross-domain rel=canonical telling them, “This one over here.” Now, even if Google crawls this other website, they are going to know that this is the original version. Pretty darn cool.
Different ways to canonicalize multiple URLs
There are different ways to canonicalize multiple URLs.
1. Rel=canonical.
I mention that rel=canonical isn’t the only one. It’s one of the most strongly recommended, and that’s why I’m putting it at number one. But there are other ways to do it, and sometimes we want to apply some of these other ones. There are also not-recommended ways to do it, and I’m going to discuss those as well.
2. 301 redirect.
The 301 redirect, this is basically a status code telling Google, “Hey, you know what? I’m going to take /b, I’m going to point it to /a. It was a mistake to ever have /b. I don’t want anyone visiting it. I don’t want it clogging up my web analytics with visit data. You know what? Let’s just 301 redirect that old URL over to this new one, over to the right one.”
3. Passive parameters in Google search console.
Some parts of me like this, some parts of me don’t. I think for very complex websites with tons of URL parameters and a ton of URLs, it can be just an incredible pain sometimes to go to your web dev team and say like, “Hey, we got to clean up all these URL parameters. I need you to add the rel=canonical tag to all these different kinds of pages, and here’s what they should point to. Here’s the logic to do it.” They’re like, “Yeah, guess what? SEO is not a priority for us for the next six months, so you’re going to have to deal with it.”
Probably lots of SEOs out there have heard that from their web dev teams….
COMMENTS