Google Confirms: 301s Better Than 302s
Yes, I am meant to be on holidays and no, I’m not meant to be posting here, but I felt this news was too important to wait another two weeks.
At the Search Summit Conference this week, I had the opportunity to ask Adam Lasnik from Google a question that I get asked a lot: Is it better to use 301 Permanently Moved or 302 Temporarily Moved redirects if you need to move a site to a new domain?
Adam replied that provided you are using the same page file names, you should absolutely use 301s rather than 302s on your old pages if you want Googlebot to re-index your site quickly. He also recommended keeping the old site live until the new site was cached and transferring the site over in different stages, depending on the number of pages it has. Google Support Engineer Maile Ohye added that you should also make sure you verify the new domain and upload your XML sitemap for it via Google Webmaster Tools to aid faster indexing.
I asked if using 301s to the new domain would be more likely to trigger the aging delay to kick in for the new site, but Adam reassured me that using 301s in combination with Google Sitemaps should make the domain relocation process fast and painless. He used an example of a 500,000 page e-commerce site he watched moving domains recently via 301s in three stages and claimed that Googlebot had entirely indexed the new site in just over five weeks.