How to move many domains form an address to another?

[Tulos]

We need to move a site from a domain to another one, and there are also hundreds or even thousands of subdomains to move.

What would be the best practise to do it in order to save at least some of the visibility in search results?

[JustinTaylor88]

Your best bet is to do a 301 redirect from the old domains to the new one.

A 301 will preserve most but not all of the link weighting etc from the old domain to the new one.

Before you redirect the domain, I would personally check it thru Open Site Explorer and if the domain has a questionable back link profile you may consider not redirecting it to the new site as as well as a 301 will take over the good as well as the bad.

If the site structure and URLs on sub pages change you may want to consider doing page by page redirects (ie olddomain/page1.html -> newdomain/pagexx.html) depending on how important or valuable the existing pages were to you in the SERPs. Page by page is the best route although much more time consuming than domain level redirects.

SEOmoz have a best practices guide on redirects which covers pretty much all you need to know
http://www.seomoz.org/learn-seo/redirection

I hope that helps

[Tulos]

Thank you Justin, you are right and that's the way we've planned to proceed.

I'm just wondering what kind of consequences it might cause if there are suddenly plenty of 301 redirections.

[Tulos]

Thank you Justin, you are right and that's the way we've planned to proceed.

I'm just wondering what kind of consequences it might cause if there are suddenly plenty of 301 redirections.

[JustinTaylor88]

The only consequence is that a 301 will pass most but not all of the link juice through to the new page.

It is quite common after site redesigns etc to have lots of 301's in place.

You may want to check out the Web Site Migration Guide blog post, it is extremely comprehensive and certainly worth a read before you embark on the transfer process.
http://www.seomoz.org/blog/web-site-migration-guide-tips-for-seos