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 -
Google Ignoring Canonical Tag for Hundreds of Sites
Bazaar Voice provides a pretty easy-to-use product review solution for websites (especially sites on Magento): https://www.magentocommerce.com/magento-connect/bazaarvoice-conversations-1.html If your product has over a certain number of reviews/questions, the plugin cuts off the number of reviews/questions that appear on the page. To see the reviews/questions that are cut off, you have to click the plugin's next or back function. The next/back buttons' URLs have a parameter of "bvstate....." I have noticed Google is indexing this "bvstate..." URL for hundreds of sites, even with the proper rel canonical tag in place. Here is an example with Microsoft: http://webcache.googleusercontent.com/search?q=cache:zcxT7MRHHREJ:www.microsoftstore.com/store/msusa/en_US/pdp/Surface-Book/productID.325716000%3Fbvstate%3Dpg:8/ct:r+&cd=2&hl=en&ct=clnk&gl=us My website is seeing hundreds of these "bvstate" urls being indexed even though we have a proper rel canonical tag in place. It seems that Google is ignoring the canonical tag. In Webmaster Console, the main source of my duplicate titles/metas in the HTML improvements section is the "bvstate" URLs. I don't necessarily want to block "bvstate" in the robots.txt as it will prohibit Google from seeing the reviews that were cutoff. Same response for prohibiting Google from crawling "bvstate" in Paramters section of Webmaster Console. Should I just keep my fingers crossed that Google honors the rel canonical tag? Home Depot is another site that has this same issue: http://webcache.googleusercontent.com/search?q=cache:k0MBLFcu2PoJ:www.homedepot.com/p/DUROCK-Next-Gen-1-2-in-x-3-ft-x-5-ft-Cement-Board-172965/202263276%23!bvstate%3Dct:r/pg:2/st:p/id:202263276+&cd=1&hl=en&ct=clnk&gl=us
Intermediate & Advanced SEO | | redgatst1 -
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 -
Proper Title Tags for ecommerce
In terms of E-commerce title tags. We are a manufacturer of our own clothing products. We are new to the SEO landscape so if this question is an obvious answer, then i apologize for wasting any one times in advance. We Manufacture our own clothing. Each item has a name. The names are American womens names such as amanda or lori or jenniffer etc. When we create the title tag for them should we include the name of the item itself at the beginning or end. For example should it be Item Name - Keyword - Keyword - Brand Name(aka manufacturer) or Keyword - Keyword - Item Name - Brand Name (aka manufacturer) The reason we ask this is because we think it would be a waste to rank for actual American names such as Jennifer and Jessica. All that we have read on Moz suggests that it seems to be better to have pertinent keywords in the beginning of the title as opposed to the end. In terms of our brand name we already rank number 1 for every combination of our brand. So we would like to start picking up traffic for the different product types we sell and there respective synonyms. Not sure if i am making any sense. Sorry in advance, and any help is very very much appreciated.
Intermediate & Advanced SEO | | Imagination0 -
Does a UTM tag influence the linkvalue?
Will Google value a link with a UTM tag the same as a clean link without a UTM tag? I should say that a UTM tag link is not a natural link so the linkvalue is zero. Anyone any idea how to look at this?
Intermediate & Advanced SEO | | TT_Vakantiehuizen0 -
Lowercase VS. Uppercase Canonical tags?
Hi MOZ, I was hoping that someone could help shed some light on an issue I'm having with URL structure and the canonical tag. The company I work for is a distributor of electrical products and our E-commerce site is structured so that our URL's (specifically, our product detail page URL's) include a portion (the part #) that is all uppercase (e.g: buy/OEL-Worldwide-Industries/AFW-PG-10-10). The issue is that we have just recently included a canonical tag in all of our product detail pages and the programmer that worked on this project has every canonical tag in lowercase instead of uppercase. Now, in GWT, I'm seeing over 20,000-25,000 "duplicate title tags" or "duplicate descriptions". Is this an issue? Could this issue be resolved by simply changing the canonical tag to reflect the uppercase URL's? I'm not too well versed in canonical tags and would love a little insight. Thanks!
Intermediate & Advanced SEO | | GalcoIndustrial0 -
Wildcard Redirects & Canonical Tags
I have an interesting situation. Current URLs Example1: www.domain.com/red-widgets-cid-1234.html
Intermediate & Advanced SEO | | NakulGoyal
www.domain.com/red-widgets-cid-1234-1.html
www.domain.com/red-widgets-cid-1234-1-1.html Canonical on All Above URLs:
www.domain.com/red-widgets-cid-1234.html New URL:
www.domain.com/red-widgets-cid-4567.html Current URLs Example2: www.domain.com/red-widgets-cid-1234+10.html
www.domain.com/red-widgets-cid-1234+10-1.html
www.domain.com/red-widgets-cid-1234+10-1-1.html Canonical on All Above URLs:
www.domain.com/red-widgets-cid-1234+10.html New URL:
www.domain.com/red-widgets-cid-6789.html Current URLs Example3: www.domain.com/red-widgets-cid-1234+10+5.html
www.domain.com/red-widgets-cid-1234+10+5-1.html
www.domain.com/red-widgets-cid-1234+10+5-1-1.html Canonical on All Above URLs:
www.domain.com/red-widgets-cid-1234+10+5.html New URL:
www.domain.com/american-red-widgets-cid-6789+5.html I want to make sure all variations of the above URL redirect to the new URLs. However, as you see in Example 3, we are dealing with variables that are passed on. (+5 in this case). Question 1: What wildcard 301 redirect / regular expression can I use to tackle these ? Question 2: If we redirect www.domain.com/red-widgets-cid-1234+10+5.html to www.domain.com/red-widgets-cid-6789+5.html and www.domain.com/red-widgets-cid-6789+5.html contains the canonical tag www.domain.com/american-red-widgets-cid-6789+5.html, any concerns or red flags here ?0 -
Should I remove Meta Keywords tags?
Hi, Do you recommend removing Meta Keywords or is there "nothing to lose" with having them? Thanks
Intermediate & Advanced SEO | | BeytzNet0