Bad canonical tag use will cause SEO havoc
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Lee
3 years ago -
2307
views
If you are looking after your own SEO on your sites you have got to make sure you are deploying the Canonical tag correctly, otherwise you can expect some spectacular falls with your positions.
What happens if you get the links in the Canonical Tag wrong?
In short – Positional Freefall!
You’ve got be careful when deploying the Canonnical tag. If you are making use of the tag then make sure you have it deployed correctly
I am still surprised there are so many sites that do not have a staging server or test facility – come on, a website is well past being fun, these things generate corporations/business serious amounts of income. So why is it that so many of you take the risk with your sites? Incorrect deployment of Canonical tag is one such risk, in fact worse than that, if you get it wrong it is a schoolboy error.
The case I’ve come up against has seen a number of positions tumble on a site, but not all. After some time running some diagnostics I started to get under the bonnet and get my hands mucky.
I have to ask the question though of how many people other than SEO’s would actually bother checking the content within the Canonical tag? From what I am seeing not many. This is a serious disconnect.
How to check for incorrect Canonical deployment
For me the are two easy ways:
1. CTRL + U that page in Firefox and let your eyes do the rest in source code view
Should your canonical tag be pointing to the home page? What if you are looking at a category or sub-category page, where are you linking that to? A simple answer is not the home page! So why are so many web designers/developers using it in this way?
2. Hover over the blue Circle in the address bar in Firefox and let the text do the talking.
If you see an error get it fixed quickly before Google does. If you don’t check your Canonical tag deployment thoroughly, you could end up with positional losses – it’s that simple.
Classic Canonical Tag Errors
Here are the common errors of deployment I have witnessed recently:
1. Missing forward slash following the domain name resulting in the pages of a site referring to OpenDNS – OUCH! (for example http://www.mysite.comcategory/product.htm)
2. Canonical reference to the home page from a category page – WHY?
3. Category pages referencing Sub-Category pages – NOT GOOD!
Three Definite Canonical ‘Do Nots’ to Remember
- Do not link rel=”canonical” to other domains (with the possible exception of sub domains)
- Do not use relative URLs
- Do not link rel=”canonical” to a broken page
Don’t forget why you should be using Canonical Tag
Big sites with plenty of pagnitaion and multiple methods of displaying products within multiple categories are an absolute given for Canonical Tag use, but why would you use the tag on your home page? Use Canonical tag where it is absolutely only necessary.
Seriously be careful when you are putting Canonical into place, it was meant to help you inform search engines which pages of your site were duplicates. Incorrect use of Canonical even in innocence or even a simple simple mistake can cause you ranking abyss.
6 comments so far to - Bad canonical tag use will cause SEO havoc -
” Do not link rel=”canonical” to other domains (with the possible exception of sub domains) ”
What was the reason for this rule of thumb ?
Google allows it actually http://googlewebmastercentral.blogspot.com/2009/12/handling-legitimate-cross-domain.html
So I got 2 domains that are almost the same but i can’t do 301. Why shouldn’t I do at least canonical from old one to new one ?
I’m interested by the comment here of “1.Do not link rel=”canonical” to other domains (with the possible exception of sub domains)”
I thought that Google specifically had announced cross domain canonical support now – I havent had a reason to implement it yet for any of my sites, but I can see some potentially good uses for this – is this something that you have tested and not found to be effective/worthwhile?
@Fedotov: How has the canonical tag worked for you with the two sites? I do not disagree that you should not be able to do it. I would always rather use a 301 where possible.
@PeterHandley: Not tested as yet, I don’t doubt the cross domain canonical does work. Based on what I have seen with results dropping with bad use of internal canonicalisation I could see further problems occurring from poor deployment of domain to domain.
I would certainly agree that I would always rather use a 301 redirect wherever possible in place of the canonical tag – and fully agree that the potential for using this badly could be potentially damaging, and would need careful planning.
It’s certainly not something that I would employ lightly, and as I said, would prefer a 301 redirect… but there are still sadly occasions when this is still frustratingly not an option for some clients.
Thank you for the information, what would happen if we dont include a canonical tag in our website?
Thank you for the information Lee, we are just completing the live information for our new website and I will be applying the information you have suggested.
Great post and keep up the good blogs!!