During the Q&A in John Mueller’s hangout on 09/24/2021, one webmaster was concerned about a site migration. Their site is number one on Google, both pages and posts.
They asked about moving a site that’s on non-www to www and how to do it without affecting SEO.
John explained that doing site migrations according to Google’s guidelines for site moves is the best option. By the way, you can find their guidelines for site migrations here.
He believes that a move from non-www to www is something that should happen fairly smoothly.
We agree. In most cases, changing from non-www to www is going to have very little impact on SEO. But also keep in mind that moving from non-www to www is actually going to make the URL longer, which is something you don’t want. You want to keep the URL as short as possible.
This exchange happens at 37:48 in the video.