How use Canonical url and does duplicate links get negative points by search engine

Question

We have website which was developed sometime back and i noticed that canonical meta tags is missing from the website even though we have few duplicate links on the website

For example home page can be accessed using three different URL

https://www.example.com/
https://www.example.com/en-us/collection/
https://www.example.com/en-us/collection/home

From my understanding canonical tag should be used on all page non-canonical page such as <link rel=“canonical” href=“https://www.example.com/” />

https://www.example.com/en-us/collection/
https://www.example.com/en-us/collection/home

Now my question are

• How badly it can effect the SEO or ranking if canonical tags are not used
• In google webmaster tools we define that www.example.com is preferred over example.com, then do i need to handle it in pages or CMS also or google will manage it for me

• If second option doesn't work then do i have to define canonical url for below url also

  https://example.com/

  https://example.com/en-us/collection/

  https://example.com/en-us/collection/home

or what is the best way to handle canonical part for website.

Answer 1

It won't effect your rankings badly, but it is in Google hands now which version will show up in the rankings. As as webmaster you want to be in control of it.

In the most CMS systems it is easier to set up a canonical for all pages. Setting up a canonical for some is most of the times harder, but can be possible as well. That's totally up to you.

So which one should be the canonical one? In this case I think I would prefer to use the root domain as canonical url. In other cases you can use the one that is most used in your internal links.

Also have a closer look at your examples. Sometimes you use a trailing slash, sometimes not.

• collection/ is not equal to collection
• collection/home is not equal to collection/home/
• but example.com/ is equal to example.com...

See John Muellers tweet about this.

Another thing about preferred versions and multiple homepage locations. If you set up redirects on your server (with .htaccess for example), you have a stable solution as well, and you don't have to worry about canonicals.

Regards, Peter