Google May Index Redirected URLs if Served in Sitemap Files
Redirects and sitemaps are both signals that Google uses to select preferred URLs. If you redirect to a destination URL but the source URL is in a sitemap, this is giving Google conflicting signals about which URL you want to be shown in search
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.
The Target Page of a Redirect Will be Used to Determine Relevance
When crawling a redirected page, Google will use the content of the target URL in order to determine the relevance of the page, as it will see different content when crawling the redirected URL.
Mixing 301 & 302 Redirects in a Chain Can Cause Confusion About Which URL Should be the Canonical
If Google encounters a mix of 301 and 302 redirects in a chain, it won’t receive clear signals on which URL should be indexed and shown in the search results. To decide this, it will take other canonicalization signals into account.
A 302 Redirect is Eventually Treated as a Permanent Redirect
A 302 redirect will be treated as a permanent redirect if it is in place for a significant amount of time, regardless of its temporary status code.
Soft 404s Cannot Be Passed to Other Pages via Redirects or Canonicals
A soft 404 cannot be passed on to another page via a canonical or redirect. Google ignores the content on a page if it detects that it is a 404 or soft 404.
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.
Rather Than Redirecting Temporary Pages, Encourage Users to Link to More Permanent Pages
If you have a page that will only be live for a short amount of time, instead of trying to consolidate link equity through redirects, John recommends encouraging users to link to more permanent pages on your site like category pages.
Redirect to an Equivalent Version When Consolidating Country Versions of a Site
If consolidating different country versions of a site, John recommends treating this as a migration and redirecting to an equivalent version e.g. redirecting the Austrian and Swiss versions of a site into one main German version. However, you cannot specify to Google that they shouldn’t show a site in particular countries.