I have old URL structure pages indexed in Google that are ranked well against the keywords. Now I have cleaned the URL structures and the new URLs have more potential to get ranked higher. Both pages are currently live.
Old URL (Ranked higher): http://www.example.com/products.asp?category=42
New URL: http://www.example.com/products/new-category
Do I have to implement 301 redirects?
If I do, will my old URL rankings drop?
Will they be replaced with the new URLs in the search results?
If you leave both on for the same page without redirection then the ranking will drop.
It is recommended that you should redirect your old URL to the new one.
Canonical: If you may have difficulty implementing redirection (301), you can place canonical in old URL or in both like:
<link rel="canonical" href="http://www.example.com/products/new-category" />
It means your clean URL will be the preferred URL.
Ranking: You may see a minor drop for a temporary period of time and then it will come back to new URL.
