The link between PageRank and website migration

In SEO, PageRank is a key element of a page's visibility in Google's results. A website migration can lower it if it is not prepared: URL changes, content reorganisation and changes to internal linking are all occasions to lose links.

PageRank is the algorithm Google developed to assess a page's importance from the links it receives. A link from a page that is itself important weighs more than a link from a page that receives few, and each page shares its value between the links it gives. Google has not shown a public PageRank since 2016, but links remain one of its signals. During a migration, these links can be changed or lost: those from other sites (see the importance of backlinks in an SEO migration) as well as those between your own pages (see internal PageRank during a migration).

A redirect sends visitors and bots from an old URL to a new one. During a migration, it is what passes the popularity earned by the old page on to the new one: Google states that a 301 or 308 redirect does not lose PageRank. Each old page still has to be redirected to its true equivalent, in a single hop: a page redirected to the home page, or left as a 404, loses the links it received. Links from other sites that point to the old site must therefore all find a redirect; see should every URL with backlinks be redirected.

• Plan the migration: identify every page and URL to redirect and prepare a redirect plan, starting with the pages that receive links and traffic.
• Check internal links: every link on the new site must point directly to the new addresses, without going through a redirect or landing on a 404 page.
• Manage backlinks: contact the sites that give you the most valuable links to ask them to point to the new URL, and update the listings and profiles you control (see keeping external popularity signals).
• Monitor after the migration: PageRank can no longer be read; follow instead the traffic, rankings, crawling and indexing of important pages in Search Console, and 404 errors.

A well-prepared migration keeps the PageRank earned and can be a chance to improve SEO: content grouped, linking rethought, useless pages removed. Swan saves you time on the longest part, matching each source page with its target page: it crawls the old site and the staging site, suggests the matches, has you validate them, then checks and exports the redirects. The full method is in our SEO migration guide.