Which sites does the Yandex robot consider mirrors?
Yandex regards sites as mirrors if they are complete or partial copies of each other. Copies are detected by matching content on pages with the same addresses (
example2.com/page.html). For example, most of the time hosts like
www.example.com are mirrors because the content on pages accessible using the same URL is identical.
Sites are also mirrors if there is a server redirect from the pages of one site to the corresponding pages on another site (
example1.com redirects to
example1.com/page.html redirects to
Does Yandex index website mirrors?
The robot groups mirrors together so that only one of them is indexed and participates in search — the main mirror.
Which site will be chosen as the main mirror? Changing the main mirror
If there is nothing pointing to which mirror should be the main one when sites are paired as mirrors, the robot chooses the main one automatically using its own algorithm.
To show the robot which URL should be the main mirror or change an existing mirror, do one of the following:
Use the Host directive.
Use a server redirect from the pages of the old domain to the corresponding pages of the new domain (we recommend using this method if the new domain is not a secondary mirror).
You can see if a site is a secondary mirror of another site by adding it to this form: Report a New Site.
You can speed up registration of changes in Yandex.Webmaster.
The main mirror isn't changed immediately, but only after some time has passed. After this, the site begins showing up in search results with the name of its new main mirror.
You can check changes using the Report a new site form.
How can I check to see if a site is a mirror?
Are characteristics of secondary mirrors transferred over to the main mirror?
Yes, they are. This helps, for example, when migrating a site to a new domain. If the old domain becomes a secondary mirror of the new one, this will help the site maintain its search ranking.
Are sites identified as mirrors if the redirects from all the pages on one of them point to the main page of the other?
Yes, the robot groups sites like this as mirrors, but we don't recommend that approach. It's better to just have redirects pointing to the corresponding pages on the other site.
I set up a server redirect to a new domain and my site no longer comes up in search results. Why?
That most likely happened because the new domain is already a secondary mirror. The old site lost its search ranking because the robot is getting a redirect code to a new site that has not yet become a main mirror and is therefore not listed in searches.
How are mirrors separated?
If sites are no longer mirrors of each other and have differing content, the robot separates them within 2–3 weeks.
You can let the robot know that it needs to separate your sites using the Main mirror tool in Yandex.Webmaster.
You can check on the status of your request to separate sites using the Report a new site form. The separation is complete once you can successfully add a site that was previously considered a secondary mirror.