There are a number of reasons you might want to change your web host, but if you do it correctly it won’t affect your Google rankings at all.
For more about this, check out the full post over at Search Engine Land.
At some point you’ll find yourself wanting to change hosts. Maybe their support has gotten worse, or you need better pricing, or some other reason has come up. When you make the move, if you do it smoothly, it won’t affect your Google rankings at all.
A user asked Google: “Our site is changing servers and I’ve had this go disastrously in the past. What do I need to do to ensure SEO is preserved?”
Google’s John Mueller responded with: ““Server migrations – where you’re just moving from one server to another, while keeping everything else the same – are pretty uneventful for Google systems. The important part is really that everything else stays the same: the URLs stay the same, the content stays the same, the CMS stays the same. It’s all the same website, just hosted on a different IP address.”
When you make a server change, your site should have literally zero downtime. When you change the DNS, over the course a few hours some people will see the old server and some will see the new one, but the site should never be down.
The one caveat is that Google may crawl your site a bit less for a while, as it checks to make sure that the new server can handle your old crawl rate. Crawling doesn’t directly affect your rankings, and that crawl rate should get back up to normal fairly quickly.