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 -
Moving html site to wordpress and 301 redirect from index.htm to index.php or just www.example.com
I found page duplicate content when using Moz crawl tool, see below. http://www.example.com
Intermediate & Advanced SEO | | gozmoz
Page Authority 40
Linking Root Domains 31
External Link Count 138
Internal Link Count 18
Status Code 200
1 duplicate http://www.example.com/index.htm
Page Authority 19
Linking Root Domains 1
External Link Count 0
Internal Link Count 15
Status Code 200
1 duplicate I have recently transfered my old html site to wordpress.
To keep the urls the same I am using a plugin which appends .htm at the end of each page. My old site home page was index.htm. I have created index.htm in wordpress as well but now there is a conflict of duplicate content. I am using latest post as my home page which is index.php Question 1.
Should I also use redirect 301 im htaccess file to transfer index.htm page authority (19) to www.example.com If yes, do I use
Redirect 301 /index.htm http://www.example.com/index.php
or
Redirect 301 /index.htm http://www.example.com Question 2
Should I change my "Home" menu link to http://www.example.com instead of http://www.example.com/index.htm that would fix the duplicate content, as indx.htm does not exist anymore. Is there a better option? Thanks0 -
Google not Indexing images on CDN.
My URL is: http://bit.ly/1H2TArH We have set up a CDN on our own domain: http://bit.ly/292GkZC We have an image sitemap: http://bit.ly/29ca5s3 The image sitemap uses the CDN URLs. We verified the CDN subdomain in GWT. The robots.txt does not restrict any of the photos: http://bit.ly/29eNSXv. We used to have a disallow to /thumb/ which had a 301 redirect to our CDN but we removed both the disallow in the robots.txt as well as the 301. Yet, GWT still reports none of our images on the CDN are indexed.
Intermediate & Advanced SEO | | alphonseha
The above screenshot is from the GWT of our main domain.The GWT from the CDN subdomain just shows 0. We did not submit a sitemap to the verified subdomain property because we already have a sitemap submitted to the property on the main domain name. While making a search of images indexed from our CDN, nothing comes up: http://bit.ly/293ZbC1While checking the GWT of the CDN subdomain, I have been getting crawling errors, mainly 500 level errors. Not that many in comparison to the number of images and traffic that we get on our website. Google is crawling, but it seems like it just doesn't index the pictures!?
Can anyone help? I have followed all the information that I was able to find on the web but yet, our images on the CDN still can't seem to get indexed.
0 -
Should I use **tags or h1/h2 tags for article titles on my homepage**
I recently had an seo consultant recommend using tags instead of h1/h2 tags for article titles on the homepage of my news website and category landing pages. I've only seen this done a handful of times on news/editorial websites. For example: http://www.muscleandfitness.com/ Can anyone weigh in on this?
Intermediate & Advanced SEO | | blankslatedumbo0 -
Best way to implement canonical tags on an ecommerce site with many filter options?
What would be the best way to add canonical tags to an ecommerce site with many filter options, for example, http://teacherexpress.scholastic.com? Should I include a canonical tag for all filter options under a category even though the pages don't have the same content? Thanks for reading!
Intermediate & Advanced SEO | | DA20130 -
Set up a rel canonical
I have a question. I was wondering, if it was possible to set up a rel canonical. When I can't access the non canonical pages? For example, my site as at www.site.com , but the non cannocail is at site.com is their any way to set thet up without actually edting it at site.com ? Thanks for your help
Intermediate & Advanced SEO | | PeterRota0 -
NOINDEX or NOINDEX,FOLLOW
Currently we employ this tag on pages we want to keep out of the index but want link juice to flow through them: <META NAME="ROBOTS" CONTENT="NOINDEX"> Is the tag above the same as: <META NAME="ROBOTS" CONTENT="NOINDEX,FOLLOW"> Or should we be specifying the "FOLLOW" in our tag?
Intermediate & Advanced SEO | | Peter2640 -
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