Are there SEO issues when splitting a subdirectory into its own domain?

Question

We have a very busy website which primary domain is news related. In addition to our website, we have a couple of subprojects, which are not news related, but are hosted on the same domain with subfolder structure. Reason for this, is because all projects under the same brand, and management prefers subfolders over subdomain.

www.ournewsportal.example
www.ournewsportal.example/project1

Due to possible brand changes, we tend to migrate one of our projects to a separate domain, but we are not sure what will that do to our SEO, not just for that subproject, but for our main domain in general. What are possible downsides and upsides of this migration?

Will the value of our domain decrease, because we will lose approx 30 million page views in our primary domain per month because of the migration.

Answer 1

Ranking for domains includes page authority and domain authority. The final results are anyones guess and depends on , but you can minimize the loss of "google juice" by doing 301 redirects from the old URL's to the new ones.

My guess if the links are high quality, over time the original site will loose SEO juice (if articles are not replaced - Google loves fresh content) while the new site will gain SEO juice. This will likely be a gradual change, but yes, if you are loosing 30 million page views it must affect your Domain authority. It might be possible to slightly mitigate this by ensuring the new site has backlinks to the old domain.