Redirects
URL redirection is a process put in place to forward site visitors to an alternative page when the page they are looking to view is no longer live on the site. Redirects may be implemented for migration purposes, as well as for site re-architecture and when pages naturally expire. They can also be used to consolidate ranking signals. Our SEO Office Hours notes below cover the different redirection types and explore how Google understands these.
Further reading: The ABCs of HTTP Status Codes
Domain Redirects Should Remain in Place Permanently
Google recommends that domain redirects should remain in place for a significant amount of time, at least a year, but it’s better to keep it in place as long as possible whilst you’re still seeing users or bots accessing the old domain.
Google Follows More than 5 Redirects In Separate Crawl Cycles
Google follows a 5 redirects during one crawl cycle, but they will continue following the redirect chains later. Once they find the final URL in the redirect chain, they will focus on that URL.
Use 301 Redirects to Inform Google of Your Preferred URL Structure
If you have a mixture of www. and non www. URLs on a site, the best way to inform Google of your preferred URL structure is to add 301 redirects with a consistent preferred domain choice.
Check Cached Page to See if Redirect Has Been Picked up by Google
Check if Google has switched the canonical version after a redirect by seeing if the cached version of the page is the target page. You can also use the GSC URL Inspection Tool to check the canonical version.
JavaScript Redirects Take Slightly Longer For Google to Process Than 301 Redirects
JavaScript redirects take longer than 301 redirects for Google to understand, as the JavaScript needs to be processed first.
Keep Old Domain & 301 Redirects for as Long as Possible After Domain Migration
John recommends maintaining 301 redirects from an old domain to the new one for at least a year after migrating. However, users may still access the old domain years after the migration, so consider keeping the redirects for as long as possible. Also try to keep ownership of the old domain so spammers don’t misuse it.
Performing URL Rewriting is the Best Way to Change the URL Structure of a Site
If you are changing the URL structure of a website, John recommends keeping the old URLs and rewriting the URLs on the server-side, if possible. This is because, from Google’s point of view, there is very little change and it’s easier to understand the content than having to reprocess all of the new URLs. If you are not able to keep the old URLs, ensure you 301 redirect from the old ones to the new ones. A redirect is a much stronger signal that you are moving content to new URLs than canonicalising them.
Use Crawlers to Detect Internal Links to Redirecting URLs After Migration
Use crawlers like Lumar to detect internal links pointing to a redirecting URL after a migration.
URL Inspection Tool Silently Processes Redirects to Display Target Page
The URL Inspection Tool generally displays the content that Google will index rather than the entered URL. If it has a redirect, this will be silently processed and the target page will be shown instead.
Google Will Not Render JavaScript Content if The Page Returns a Redirect or Error Code
If you have a page which contains JavaScript content but it returns a redirect or an error code, Google will not spend time rendering the content. For example, if you use JavaScript on a 404 page to display an error message or links. With redirects, Google does not need to render the content in order to follow the redirect to the new page.