Moz Q&A is closed.
After more than 13 years, and tens of thousands of questions, Moz Q&A closed on 12th December 2024. Whilst we’re not completely removing the content - many posts will still be possible to view - we have locked both new posts and new replies. More details here.
How does a canonical work and is it necessary to also have a no index, follow tag in place?
-
Across our site, we have canonical tags in place for URLs that contain duplicate content and for URLs without a trailing slash since we are using URLs WITH a trailing slash for all URLs across our site. We also recently added a no index, follow tag to all non-canonical URLs since we noticed a high number of duplicate content URLs in Google Webmaster Tools.
The first part of my question is: How does a canonical work? Does the robot read the canonical and immediately go to the canonical URL or does it continue to read past the canonical tag and get to the no index, follow tag if there is one present?
The second part of my question is: Is it necessary to have both a canonical tag and no index, follow tag in place? Or should the canonical tag be sufficient to avoid duplicate content?
And lastly, if both a canonical tag and no index, follow tag are in place, should they be in a specific order? Canonical tag first then no index, follow tag second or no index, follow tag first then canonical tag second?
I would appreciate any insight you can give. Thank you!
-
Thank you for you responses and advice!
-
Very nice addition John.
-
Ryan, spot on as always.
One other thing, it sounds like some of the canonicals you're placing on pages would be better suited to 301 redirects, like correcting a URL for not having a trailing slash or not. If you can avoid using canonicals and use 301 redirects instead, that's the preferred method for resolving duplicate content issues. Canonicals are more for when there are parameters on the URLs, and you can't get away from serving the pages with those parameters.
-
How does a canonical work? Does the robot read the canonical and immediately go to the canonical URL or does it continue to read past the canonical tag and get to the no index, follow tag if there is one present?
The first thing to understand is the canonical tag is a suggestion, not an order. While a search engine will usually honor the canonical tag, there are instances where Google or other SEs may determine the canonical tag is not being used correctly so they disregard the canonical tag. Based on this understanding, yes the robot will read the entire page regardless of the canonical tag status.
Is it necessary to have both a canonical tag and no index, follow tag in place? Or should the canonical tag be sufficient to avoid duplicate content?
The two tags you mention conflict. You would never use both tags on the same page.
Noindex means you do not wish the page to appear in the search index. The canonical tag means you do wish the content to be included in the search index, but use the canonical URL in the index.
if both a canonical tag and no index, follow tag are in place, should they be in a specific order?
The order of meta tags does not matter. If a page was marked with both a canonical tag and a noindex tag, the noindex tag would take effect and the page would not be indexed, so the canonical tag would not have any effect.
In short, you want to use the canonical tag to resolve duplicate content issues, not the noindex tag.
Got a burning SEO question?
Subscribe to Moz Pro to gain full access to Q&A, answer questions, and ask your own.
Browse Questions
Explore more categories
-
Moz Tools
Chat with the community about the Moz tools.
-
SEO Tactics
Discuss the SEO process with fellow marketers
-
Community
Discuss industry events, jobs, and news!
-
Digital Marketing
Chat about tactics outside of SEO
-
Research & Trends
Dive into research and trends in the search industry.
-
Support
Connect on product support and feature requests.
Related Questions
-
Canonical and Alternate Advice
At the moment for most of our sites, we have both a desktop and mobile version of our sites. They both show the same content and use the same URL structure as each other. The server determines whether if you're visiting from either device and displays the relevant version of the site. We are in a predicament of how to properly use the canonical and alternate rel tags. Currently we have a canonical on mobile and alternate on desktop, both of which have the same URL because both mobile and desktop use the same as explained in the first paragraph. Would the way of us doing it at the moment be correct?
Intermediate & Advanced SEO | | JH_OffLimits3 -
Canonical Chain
This is quite advanced so maybe Rand can give me an answer? I often have seen questions surrounding a 301 chain where only 85% of the link juice is passed on to the first target and 85% of that to the next one, up to three targets. But how about a canonical chain? What do I mean by this:? I have a client who sells lighting so I will use a real example (sans domain) I don't want 'new-product' pages appearing in SERPS. They dilute link equity for the categories they replicate and often contain identical products to the main categories and subcategories. I don't want to no index them all together I'd rather tell Google they are the same as the higher category/sub category. (discussion whether a noindex/follow tag would be better?) If I canonicalize new-products/ceiling-lights-c1/kitchen-lighting-c17/kitchen-ceiling-lights-c217 to /ceiling-lights-c1/kitchen-lighting-c17/kitchen-ceiling-lights-c217 I then subsequently discover that everything in kitchen-ceiling-lights-c217 is already in /kitchen-lighting-c17 and I decide to canonicalize those two - so I place a /kitchen-lighting-c17 canonical on /kitchen-ceiling-lights-c217. Then what happens to the new-products canonical? Is it the same rule - does it pass 85% of link equity back to the non new-product URL and 85% of that back to the category? does it just not work? or should I do noindexi/follow Now before you jump in: Let's assume these are done over a period of time because the obvious answer is: Canonicalize both back to /ceiling-lights-c1/kitchen-lighting-c17 I know that and that is not what I am asking. What if they are done in a sequence what is the real result? I don't want to patronise anyone but please read this carefully before giving an answer. Regards Nigel Carousel Projects.
Intermediate & Advanced SEO | | Nigel_Carr0 -
H2 Tags- Can you have more than 1 H2 tag
Hi All, Screaming frog has identified that we have a few H2 tags on our pages , although we only have 1 H1 tag. We have numerous H3,H4's etc. I am wondering, is it good SEO to have only 1 H2 tag like with H1 tag or can you have more ? thanks Peter
Intermediate & Advanced SEO | | PeteC120 -
Duplicate Title tags even with rel=canonical
Hello, We were having duplicate content in our blog (a replica of each post automatically was done by the CMS), until we recently implemented a rel=canonical tag to all the duplicate posts (some 5 weeks ago). So far, no duplicate content were been found, but we are still getting duplicate title tags, though the rel=canonical is present. Any idea why is this the case and what can we do to solve it? Thanks in advance for your help. Tej Luchmun
Intermediate & Advanced SEO | | luxresorts0 -
301s being indexed
A client website was moved about six months ago to a new domain. At the time of the move, 301 redirects were setup from the pages on the old domain to point to the same page on the new domain. New pages were setup on the old domain for a different purpose. Now almost six months later when I do a query in google on the old domain like site:example.com 80% of the pages returned are 301 redirects to the new domain. I would have expected this to go away by now. I tried removing these URLs in webmaster tools but the removal requests expire and the URLs come back. Is this something we should be concerned with?
Intermediate & Advanced SEO | | IrvCo_Interactive0 -
Rel="canonical" and rel="alternate" both necessary?
We are fighting some duplicate content issues across multiple domains. We have a few magento stores that have different country codes. For example: domain.com and domain.ca, domain.com is the "main" domain. We have set up different rel="alternative codes like: The question is, do we need to add custom rel="canonical" tags to domain.ca that points to domain.com? For example for domain.ca/product.html to point to: Also how far does rel="canonical" follow? For example if we have:
Intermediate & Advanced SEO | | AlliedComputer
domain.ca/sub/product.html canonical to domain.com/sub/product.html
then,
domain.com/sub/product.html canonical to domain.com/product.html0 -
Redirecting index.html to the root
Hi, I was wondering if there is a safe way to consolidate link juice on a single version of a home page. I find incoming links to my site that link to both mysite.com/ and mysite.com/index.html. I've decided to go with mysite.com/ as my main and only URL for the site and now I'd like to transfer all link juice from mysite.com/index.html to mysite.com/
Intermediate & Advanced SEO | | romanbond
When i tried 301 redirect from index.html to the root it created an indefinite loop, of course. I know I can use a RewriteRule.., but will it transfer the juice?? Please help!7 -
Any penalty for having rel=canonical tags on every page?
For some reason every webpage of our website (www.nathosp.com) has a rel=canonical tag. I'm not sure why the previous SEO manager did this, but we don't have any duplicate content that would require a canonical tag. Should I remove these tags? And if so, what's the advantage - or disadvantage of leaving them in place? Thank you in advance for your help. -Josh Fulfer
Intermediate & Advanced SEO | | mhans1