Google's John Mueller said on Friday in a webmaster video that redirecting all of your URLs to your home page is bad practice. Instead, you should redirect those URLs on a one by one basis to the proper new location.
This is common sense to most SEOs but I've seen many sites do a redesign and new CMS and just redirect all the old URLs to the home page and not try to redirect those URLs to the new URL with the same content on the old URL.
John said this at the 1 hour 6 minute and 10 second mark; "redirecting everything to just the homepage is a really bad practice." " Because we lose all of the signals that are associated with the the old content if you're just saying well the homepage replaces all of these lower level pages" he added.
You will confuse Google and Google might say it doesn't make sense to redirect all those signals to your home page. John said this is a "really bad kind of technique."
Here is the video embed:
Here is the transcript:
So generally, as you probably noticed redirecting everything to just the homepage is a really bad practice. Because we lose all of the signals that are associated with the the old content if you're just saying well the homepage replaces all of these lower level pages.So that's really bad kind of technique I strongly recommend if you do any kind of site move to really double-check that you're redirecting on a one to one URL basis. And especially if you're just changing domain names really to make sure that all of the old content redirects to exactly the same thing new content on the new domain. So as much as possible to really make it clear to those algorithms that you're not providing a new website, you're not changing anything like general across your website, you're just moving everything from this URL to a new URL.
And if we can recognize that it's really a clear one-to-one move, then it's a lot easier for us to say oh we will just like take all of these signals and pass them on to the new domain structure because it's really one to want exactly the same thing.
Forum discussion at YouTube.