There is no Harm in Redirecting Parked Domains to a Live Website
If you have parked domains redirecting to your main site, for example for offline marketing purposes, there is no negative impact from an SEO perspective.
Use Redirects & Canonical Tags to Stop Data From Other Site on Same IP Being Included in GSC
If there are internal links between two sites on the same IP address, data for both sites can sometimes appear in the same GSC account. If you don’t want Google crawling the other site then add redirects or canonical tags pointing to the main site.
Implement Redirects From Mobile Pages to Desktop Pages For Desktop Users
If you have a separate m-dot site, Google will usually pick this as the preferred canonical version after mobile-first indexing and the m-dot site will be shown in desktop search results. To avoid negative UX, implement redirects to the desktop version for desktop users.
Redirects Can Impact Crawl Budget Due to Added Time for URLs to be Fetched
If there are a lot of redirects on a site, this can impact crawl budget as Google will detect that URLs are taking longer to fetch and will limit the number of simultaneous requests to the website to avoid causing any issues to the server.
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.