Google will pass permanent signals with a redirect after a year
We know Google has told us to leave our redirects up for at least a year, but now, Gary Illyes from Google said the “concrete answer” after he dug into how Google Search handles it internally, is to leave your redirect up for “at least one year.” This will result in Google passing any signals from the original URL to the destination URL from the time Google found the redirect, to the time Google noticed the redirect was removed.
That means, the signals passed from the original URL to the destination URL will always be associated with the destination URL, even after you remove the redirect. But after you do remove the redirect, the signals going forward will then be associated with the original URL and not the destination URL.
What about the signals passing?
So Gary Illyes and a bunch of SEOs went back and forth trying to clarify what this means. I summed it up above but here is Patrick Stox, a long time SEO, summing up Gary Illyes’ clarification:
Technically, it can be less than a year, but to be safe, keep it up for a year to be safe that the signals will stick with the destination URL.
Also for users, you probably want to keep the redirect up for as long as possible. But that is up to you.
A final point, which I mentioned above, is that the clock starts ticking when Google first discovers the redirect. So if you are tracking it that closely, it is based on the time Google crawled the redirect, not when you actually put up the redirect.
Why we care.
This is the first time Google has officially confirmed that the signals passed through redirects last forever even after a redirect is moved if the redirect is live for over a year.
So now if you have clients that really want to remove redirects for whatever reason, if the redirect is live for a year or more, it is safe to do so from an SEO perspective specific to Google Search.
More importantly, if the redirect is removed over time because of just normal maintenance and it has been a year, you still do not need to worry.