A HTTPS migration involves moving a domain from a HTTP protocol to a secure HTTPS protocol. Similar to a domain migration, there are several factors to consider to ensure the migration runs smoothly. We cover these within our Hangout Notes, along with further recommendations from Google.
Make Sure Hosting & Redirects Are Set Up Correctly After Migration so Google Doesn’t Think Site is Offline
If part of your website doesn’t work when Google is trying to access it, such as www. pages, Google could assume that the site has gone offline. Ensure that redirects and the hosting is set up correctly to avoid this from happening.
Google Can Process HTTPS Migrations Implemented With 302 Redirects
Even though it is recommended to use 301 redirects where possible for site migrations, John explained that Google often sees the wrong types of redirects implemented and has adapted to try and handle this.
Having HTTP Version in Google Listings or Snippets Can Drive Impressions Even After HTTPS Migration
If you’re seeing impressions and clicks for the HTTP version of your site after migrating to HTTPS, this could be because the HTTP version is linked to somewhere externally in a knowledge box or your Google My Business listing, for example.
Inconsistent HTTPS Migrations Cause Bigger Ranking Fluctuations
Google is more cautious with inconsistent HTTPS migrations that don’t map one to one from HTTP to HTTPS with clear 301 redirects. HTTPS migrations that also remove a lot of URLs or block URLs by robots.txt are likely to see bigger fluctuations in rankings.
Using Non-301 Redirects For Migration Causes Google to Reprocess Each URL
For a HTTPS migration, use 301 redirects rather than 302 or 303 redirects as the 301 is a cleaner signal for Google to process a migration. Non-301 redirects can cause Google to reprocess each URL individually.
HSTS Isn’t Used as a Ranking Signal
HSTS doesn’t play any part in rankings. The main consideration from Google’s perspective is that it shouldn’t be added to a site during a time of fluctuation, like a migration. Make sure you only add it once rankings have settled and a migration has been completed successfully.
A/B Testing During a Site Migration Can Delay Google Processing the Move
If you’re running large scale A/B testing during a site migration, this can confuse Google’s picture of your site and prevent it from running an algorithm to easily switch all of your URLs across to the new version.
GSC Messages For HTTP Version After HTTPS Migration Could Mean Signals Pointing to HTTP
John recommends having the HTTP and HTTPS versions of your site verified in Search Console. If you still receive messages after a HTTPS migration it could mean that some signals are still pointing to the HTTP version.
Google Uses Multiple Signals to Choose HTTP or HTTPS URLs
Redirects, internal links, sitemaps, rel canonicals are taken into consideration when Google chooses to index a page on HTTP or HTTPS. Internal links to HTTP URLs after a migtration to HTTPS will give Google conflicting signals, but usually there will be enough signals to indicate that the HTTPS version should be indexed.