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.
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?
-
That would normally be the case but not tonight.
LOL, I am picking up a lot of the UK Q&A I will be at BrightonSEO and search love London if any of you guys will be in the area I'd love to grab a pint?
sincerely,
Thomas
-
The reason we answered 'quickly' by the way is because we are in the UK - you were still in bed lol!
-
There is only ONE URL that is the point.
If they share the same URL then you only have one page of code so ONE canonical
Regards
Nigel
-
Sorry Nigel
was not trying to make this more complicated was just trying to make sure that we were all on the same page.
FYI if you need a method of adding the rel canonical to your website quickly you can use Google tag manager or if you want to add to the header
https://support.stackpath.com/hc/en-us/articles/360001445283-EdgeRules-Adding-a-Canonical-Header
-
So a self referencing canonical on both mobile and desktop versions of the site, regardless if they chuck out two version with the same content?
-
Hi JH
I'm sure Thomas means well with his multiple complicated posts but all of this is totally unnecessary.
Both sites are serving the same URL
You can't put a rel=alternative because there is nothing to point to.
Just put a self-referencing canonical. I said that 2 hours ago!
That is all.
Regards Nigel
-
Use a self-referencing canonical
https://blog.seoprofiler.com/google-recommend-self-referencing-canonical-tags/
Please let me know if you want me to remove the image below?
you can use this one if needed http://bseo.io/c1vMSv
-
I've been told to pass on a URL, thanks for your help Thomas!
-
Hey man I understand is a big deal
could you do me a huge favor and run your site through screaming frog SEO spider send me a couple of pages with the domains whited out so I can tell you 100% what to do in this situation because I am basing this on what you have told me and honestly I would like to look at what a tool can show me and that will tell me what I need to do.
Or you can tell me if the mobile version of the site hit's Google's index yes or no?
respectfully,
Tom
-
So both mobile and desktop require a self referencing canonical(in both headers)?
Sorry for the questions, just need to make sure! It's a very touchy subject!
-
The single self-referencing URL will work.
-
What URLs are you using with the “alternate” tag on?
You said
”1. We have multiple brand sites, that have a similar setup. They all have mobile and desktop versions of the sites running on the same URL, both of which show the same content.2. The server determines whether if you're on a desktop or mobile devices using the header information, and points the user to the site relevant files for the given device.”
thats Dynamic serving same URL
Dynamic serving is a setup where the server responds with different HTML (and CSS) on the same URL depending on which user agent requests the page (mobile, tablet, or desktop).
that would NOT give you the mobile or m.example.com & www.example.com different URLs
**But If you do have a different m.example.com & www.example.com URLs you should use this code or XML site maps **
for different URLs use this:
Annotations in the HTML
On the desktop page (http://www.example.com/page-1), add the following annotation:
<linkrel="alternate"media="only screen="" and="" (max-width:="" 640px)"<="" span="">href="http://m.example.com/page-1"></linkrel="alternate"media="only>
On the mobile page (http://m.example.com/page-1), the required annotation should be:
<linkrel="canonical"href="http: www.example.com="" page-1"=""></linkrel="canonical"href="http:>
This rel="canonical" tag on the mobile URL pointing to the desktop page is required.
Or
Annotations in sitemaps
We support including the rel="alternate"annotation for the desktop pages in sitemaps like this:
<urlsetxmlns="http: www.sitemaps.org="" schemas="" sitemap="" 0.9"<="" span="">xmlns:xhtml="http://www.w3.org/1999/xhtml">
<loc>http://www.example.com/page-1/</loc>
<xhtml:linkrel="alternate"media="only screen="" and="" (max-width:="" 640px)"<="" span="">href="http://m.example.com/page-1"/></xhtml:linkrel="alternate"media="only></urlsetxmlns="http:>You should have the same URL on mobile and desktop
You should have the same rel canonical tag on your URLs unless and this is a big unless you're talking about using Google AMP?
If the URL you want to be indexed is the same URL point everything to that URL if that makes it easier to understand.
respectfully,
Tom
-
Just to confirm, are we suppose to have a canonical on desktop and mobile or just desktop?
This would mean removing the alternate?
Want to confirm everything before iterating this across to others.
We are not using AMP, just a standard site setup.
-
Unless you are using AMP?
Then you would add
Linking pages with
In order to solve this problem, we add information about the AMP page to the non-AMP page and vice versa, in the form of tags in the .
Add the following to the non-AMP page:
<link rel="amphtml" href="https://www.example.com/url/to/amp/document.html">
And this to the AMP page:
<link rel="canonical" href="https://www.example.com/url/to/full/document.html">
are you using AMP pages?
https://support.google.com/webmasters/answer/139066?hl=en
https://www.ampproject.org/docs/fundamentals/discovery
I hope that helps you if not please let me know.
Respectfully,
Tom
-
Cool, that's what I thought when I heard your description I just wanted to be very thorough because sometimes you get very little information and I appreciate you letting me know that.
dynamic serving URLs are identical to each other so you should have a self-referencing canonical tag because the URL does not change the real canonical tag just decides what should be in the index and the same URL.
You're Rel canonical should be something like this example below
Example URL https://www.example.com/example-url/
because the end URL is the same and URL that you want to be indexed in Google you want to be certain that you have a self-referencing URL to prevent query strings and other things like that and you do not need to point a URL to an identical URL you just need a self-referencing canonical if that makes sense.
See: https://yoast.com/rel-canonical/
I hope that is of help,
Tom
-
Hi,
I can't give off too much information as it's not my call, but I can answer your questions without mentioning the brands.
1. We have multiple brand sites, that have a similar setup. They all have mobile and desktop versions of the sites running on the same URL, both of which show the same content.
2. The server determines whether if you're on a desktop or mobile devices using the header information, and points the user to the site relevant files for the given device.
3. Our sites would quite clearly fit in the dynamic serving category.
We have 301 redirects on none www to www and http to https.
-
This is the correct solution!
-
The URLs are identical it is just the content that is served that may be slightly different.
Since you can only specify one canonical for each URL it makes no difference. Just self-reference and that is it.
If you had to different URLs then it would be an issue where you woudl need a rel=alternative so there is nothing to worry about.
Regards
Nigel
-
You guys are fast I was going to answer this and had to do some other things but let me weigh in on couple things.
as you said
“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.”**
so what you’re saying is that you have a dynamic site so you don’t need to add “alternate"media” tags to the site.
https://developers.google.com/search/mobile-sites/mobile-seo/dynamic-serving
As it is not immediately apparent in this setup that the site alters the HTML for mobile user agents (the mobile content is "hidden" when crawled with a desktop user agent), it’s recommend that the server send a hint to request that Googlebot for smartphones also crawl the page, and thus discover the mobile content. This hint is implemented using the Vary HTTP header.
**you don’t need this **
Annotations in the HTML
On the desktop page (
http://www.example.com/page-1
), add the following annotation:<code dir="ltr"><linkrel="alternate"media="only screen="" and="" (max-width:="" 640px)"<br="">href="http://m.example.com/page-1"></linkrel="alternate"media="only></code>
On the mobile page (
http://m.example.com/page-1
), the required annotation should be:<code dir="ltr"><linkrel="canonical"href="http: www.example.com="" page-1"=""></linkrel="canonical"href="http:></code>
This
rel="canonical"
tag on the mobile URL pointing to the desktop page is required.Annotations in sitemaps
We support including the
rel="alternate"
annotation for the desktop pages in sitemaps like this:<code dir="ltr"><urlsetxmlns="http: www.sitemaps.org="" schemas="" sitemap="" 0.9"<br="">xmlns:xhtml="http://www.w3.org/1999/xhtml"> <url><loc>http://www.example.com/page-1/</loc> <xhtml:linkrel="alternate"media="only screen="" and="" (max-width:="" 640px)"<br="">href="http://m.example.com/page-1"/></xhtml:linkrel="alternate"media="only></url></urlsetxmlns="http:></code>
The required
rel="canonical"
tag on the mobile URL should still be added to the mobile page's HTML.**to be sure **
Are you willing to share your domain with us? Or one domain?
-
We're talking about multiple websites that all have the identical site structure or at least mobile and desktop site structure?
-
Your server is making the change for you?
-
Would you be kind enough to install this plug-in on chrome in order for you to show a couple examples of the canonical and the URL?
- https://chrome.google.com/webstore/detail/portents-seo-page-review/babgchcegnkbiojmdpnoilficladccfm?hl=en-US
- https://chrome.google.com/webstore/detail/link-redirect-trace/nnpljppamoaalgkieeciijbcccohlpoh?hl=en
In addition, would you be kind enough to run your site through the two tools here ( 100% free and very easy to use)
If you would not mind doing this and sending screenshots it would mean a lot to us and getting your canonical's straightened out.
screenshots https://snag.gy/ then upload to http://imgur.com/
everything is on the same server I'm assuming?
Of the three below how would you categorize your site?
- https://developers.google.com/search/mobile-sites/mobile-seo/separate-urls
- https://developers.google.com/search/mobile-sites/mobile-seo/dynamic-serving
- https://developers.google.com/search/mobile-sites/mobile-seo/responsive-design
Respectfully,
Tom
-
-
Would this mean we need canonical only on desktop or mobile site?
-
You are right - you could only use teh rel=alternate if there was an m. version or similar
Regards
Nigel
-
The self referencing canonical advice was solid and I 100% agree with it. The rel=alternate advice, I felt would cause problems (IMO). But as we all know, fiddly issues like this are highly subjective
-
Then there is no problem simply putting a self-referencing canonical. There is in effect no mobile version as there is a single URL so no need for a rel=alternate.
It's an even easier solution. Well, there isn't a problem in the first place.
rel=alternate is only necessary if you have two different URLs! The fact they are the same takes away the problem.
Regards
Nigel
-
Your problem is that you have two different sites loading on the same URL. If you are returning both the mobile and desktop / laptop site on the same URL, you would be expected to be using responsive design. In-fact, you may have re-invented another different way to implement responsive design which is probably, slightly less fluid yet slightly more efficient :')
Since your mobile and desktop pages both reside on exactly the same URL, I'd test the page(s) with this tool (the mobile friendly tool) and this tool (the page-speed insights tool). If Google correctly views your site as mobile friendly, and if within PageSpeed insights Google is correctly differentiating between the mobile and desktop site versions (check the mobile and desktop tabs) then both URLs should canonical to themselves (self referencing canonical) and no alternate tag should be used or deployed. Google will misread the alternate tag, which points to itself - as an error. That tag is to be used when your separate mobile site (page) exists on a separate URL, like an 'm.' subdomain or something like that
Imagine you are Googlebot. You are crawling in desktop mode, load the desktop URL version and find that the page says, it (itself) is also the mobile page. You'd get really confused
Check to see whether your implementation is even supported by Google using the tools I linked you to. If it is, then just use self referencing canonical tags and do not deploy alternate tags (which would make no sense, since both versions of the site are on the same URL). When people build responsive sites (same source code on the same URL, but it's adaptive CSS which re-organises the contents of the page based upon viewport widths) - they don't use alternate tags, only canonicals
Since your situation is more similar to responsive design (from a crawling perspective) than it is to separate mobile site design, drop the alt
-
The problem with this is, where you say "corresponding mobile URL" - there isn't one as OP has stated that, two different source codes (pages) can be rendered on the same URL depending upon the user's screen size / user-agent (however they are detecting mobile, and serving different pages)
-
Hi JH
This is very straightforward.
Use the following annotations:
- On the desktop page, add a rel=”alternate” tag pointing to the corresponding mobile URL. This helps Googlebot discover the location of your site’s mobile pages.
- On the mobile page, add a link rel=”canonical” tag pointing to the corresponding desktop URL.
It is that simple and doing this will not create duplicate content
More here: https://developers.google.com/search/mobile-sites/mobile-seo/separate-urls
Regards Nigel
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
-
Move to new domain using Canonical Tag
At the moment, I am moving from olddomain.com (niche site) to the newdomain.com (multi-niche site). Due to some reasons, I do not want to use 301 right now and planning to use the canonical pointing to the new domain instead. Would Google rank the new site instead of the old site? From what I have learnt, the canonical tag lets Google know that which is the main source of the contents. Thank you very much!
Intermediate & Advanced SEO | | india-morocco0 -
Is it best practice to have a canonical tags on all pages
The website I'm working on has no canonical tags. There is duplicate content so rel=canonicals need adding to certain pages but is it best practice to have a tag on every page ?
Intermediate & Advanced SEO | | ColesNathan0 -
Attribution of port number to canonical links...ok?
Hi all A query has recently been raised internally with regard to the use of canonical links. Due to CMS limitations with a client who's CMS is managed by a third party agency, canonical links are currently output with the port number attributed, e.g. example.com/page:80 ...as opposed to the correct absolute URL: example.com/page Note port number are not attributed to the actual page URLs. We have been advised that this canonical link functionality cannot be amended at present. My personal interpretation of canonical link requirements is that such a link should exactly match the absolute URL of the intended destination page, my query is does this extend to the attribution of port number to URLs. Is the likely impact of the inclusion of such potentially incorrect URLs likely to be the same as purely incorrect canonical links. Thanks
Intermediate & Advanced SEO | | 26ryan0 -
Exact Syntax for Canonical to PDFs for Windows Server
Hi There, I have got in my web several PDFs with the same content of the HTML version. Thus I need to set up a canonical for each of them in order to avoid duplicate content. In particular, I need to know how to write the exact syntax for the windows server (web.config) in order to implement the canonical to PDF. I surfed the web but it seems I cannot find this piece of info anywhere Thanks a lot!!
Intermediate & Advanced SEO | | Midleton0 -
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 -
Canonical tag - but Title and Description are slightly different
I am building a new SEO site with a "Silo" / Themed architecture. I have a travel website selling hotel reservations. I list a hotel page under a city page - example, www.abc.com/Dallas/Hilton.html Then I use that same property under a segment within the city - example www.abc.com/Dallas/Downtown/Hilton.html, so there are two URLs with the same content Both pages are identical, except I want to customize the Title and Description. I want to customize the title and description to build a consistent theme - for example the /Downtown/Hilton page will have the words "Near Downtown" in the Title and Description, while the primary city Hilton page will not. So I have two questions about this. First, is it okay to use a canonical tag if the Title and Description are slightly different? Everything else is identical. If so, will Google crawl and comprehend the unique Title and Description on the "Downtown" silo? I want Google to see that I have several "supporting" pages to my main landing page(s). I want to present to Google 5 supporting pages in each silo that each has a supporting keyword theme. But I'm not sure if Google will consider content of pages that point to a different page using the canonical tag. Please see this supporting example: http://d.pr/i/aQPv Thanks for your insights. Rob
Intermediate & Advanced SEO | | partnerf0 -
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 -
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