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
-
No index detected in robots meta tag GSC issue_Help Please
Hi Everyone, We just did a site migration ( URL structure change, site redesign, CMS change). During migration, dev team messed up badly on a few things including SEO. The old site had pages canonicalized and self canonicalized <> New site doesn't have anything (CMS dev error) so we are working retroactively to add canonicalization mechanism The legacy site had URL’s ending with a trailing slash “/” <> new site got redirected to Set of url’s without “/” New site action : All robots are allowed: A new sitemap is submitted to google search console So here is my problem (it been a long 24hr night for me 🙂 ) 1. Now when I look at GSC homepage URL it says that old page is self canonicalized and currently in index (old page with a trailing slash at the end of URL). 2. When I try to perform a live URL test, I get the message "No: 'noindex' detected in 'robots' meta tag" , so indexation cant be done. I have no idea where noindex is coming from. 3. Robots.txt in search console still showing old file ( no noindex there ) I tried to submit new file but old one still coming up. When I click on "See live robots.txt" I get current robots. 4. I see that old page is still canonicalized and attempting to index redirected old page might be confusing google Hope someone can help to get the new page indexed! I really need it 🙂 Please ping me if you need more clarification. Thank you ! Thank you
Intermediate & Advanced SEO | | bgvsiteadmin1 -
Multiple H2 tags
Is it advisable to use only one H2 tag? The template designs for some reason is ended up with multiple H2 tags, I realise if any think it's that each one is that are important and it is all relative. Just trying to assess if it's worth the time and effort to rehash the template. Has anyone done any testing or got any experience? Thanks
Intermediate & Advanced SEO | | seoman101 -
How to add Canonical Tags on Opencart Products
Does anyone know how to add canonical tags to product pages in Opencart? Is this possible to do in htaccess? If so, how specifically should it be written in? Please do not post any links to other pages which reference generic canonical information as I've read them all and none help. I'm looking for an Opencart specific answer, or a way to do it in htaccess.
Intermediate & Advanced SEO | | moon-boots0 -
Null Alt Image Tags vs Missing Alt Image Tags
Hi, Would it be better for organic search to have a null alt image tag programatically added to thousands of images without alt image tags or just leave them as is. The option of adding tailored alt image tags to thousands of images is not possible. Is having sitewide alt image tags really important to organic search overall or what? Right now, probably 10% of the sites images have alt img tags. A huge number of those images are pages that aren Thanks!
Intermediate & Advanced SEO | | 945010 -
Partial duplicate content and canonical tags
Hi - I am rebuilding a consumer website, and each product page will contain a unique product image, and a sentence or two about the product (and we tend to use a lot of the same words in different ways across products). I'd like to have a tabbed area below the product info that talks about the overall product line, and this content would be duplicate across all the product pages (a "Why use our products" type of thing). I'd have this duplicate content also living on its own URL's so they can be found alone in the SERP's. Question is, do I need to add the canonical tag to this page, since there's partial duplicate content on the product pages? And if I did that, would my product pages go un-indexed?? I understand how to handle completely duplicated content, it's the partial duplicate that I'm having difficulty figuring out.
Intermediate & Advanced SEO | | Jenny10 -
Google Indexing Feedburner Links???
I just noticed that for lots of the articles on my website, there are two results in Google's index. For instance: http://www.thewebhostinghero.com/articles/tools-for-creating-wordpress-plugins.html and http://www.thewebhostinghero.com/articles/tools-for-creating-wordpress-plugins.html?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+thewebhostinghero+(TheWebHostingHero.com) Now my Feedburner feed is set to "noindex" and it's always been that way. The canonical tag on the webpage is set to: rel='canonical' href='http://www.thewebhostinghero.com/articles/tools-for-creating-wordpress-plugins.html' /> The robots tag is set to: name="robots" content="index,follow,noodp" /> I found out that there are scrapper sites that are linking to my content using the Feedburner link. So should the robots tag be set to "noindex" when the requested URL is different from the canonical URL? If so, is there an easy way to do this in Wordpress?
Intermediate & Advanced SEO | | sbrault740 -
Should I prevent Google from indexing blog tag and category pages?
I am working on a website that has a regularly updated Wordpress blog and am unsure whether or not the category and tag pages should be indexable. The blog posts are often outranked by the tag and category pages and they are ultimately leaving me with a duplicate content issue. With this in mind, I assumed that the best thing to do would be to remove the tag and category pages from the index, but after speaking to someone else about the issue, I am no longer sure. I have tried researching online, but there isn't anything that provided any further information. Please can anyone with any experience of dealing with issues like this or with any knowledge of the topic help me to resolve this annoying issue. Any input will be greatly appreciated. Thanks Paul
Intermediate & Advanced SEO | | PaulRogers0 -
Canonical Tag and Affiliate Links
Hi! I am not very familiar with the canonical tag. The thing is that we are getting traffic and links from affiliates. The affiliates links add something like this to the code of our URL: www.mydomain.com/category/product-page?afl=XXXXXX At this moment we have almost 2,000 pages indexed with that code at the end of the URL. So they are all duplicated. My other concern is that I don't know if those affilate links are giving us some link juice or not. I mean, if an original product page has 30 links and the affiliates copies have 15 more... are all those links being counted together by Google? Or are we losing all the juice from the affiliates? Can I fix all this with the canonical tag? Thanks!
Intermediate & Advanced SEO | | jorgediaz0