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After some consideration, we have decided to change the product URLs on a particular site back to a flat structure, to avoid duplicate content issues.
The problem is, there are tons of links already out there in the world that still contain the various categories, and those URLs still work. Is there any way to make those URLs 404, so we can redirect them to the current, flat URLs?
Can you just 301 redirect the old URL’s to the new URL’s on the new site structure? You’ll want to update your sitemap as well and resubmit it to Google and Bing. That way if someone lands on an old page, they’re redirected to the current one.
Or if you have old pages like that, you can 404 them, but then suggest to the user to find what they’re looking for in the section or pages you want.