I'm very inexperienced when it comes to redirects. My main this is i don't want to lose my search engine page rankings and search engine traffic. Anyway I have a blog and I'm working on a major redesign/rebuild. I want to change my post permalink structure. Currently it looks like this: /:category/:permalink Code (markup): and I'll be changing it to: /:permalink Code (markup): Do the redirects have to stay up forever? or will google get the message after a while? I can either do this in nginx or in the rails router file, I'd assume doing it in nginx would be better right? Could someone explain how to do this? Thanks!
If your rankings are good and your getting traffic, then don't do it! Your rankings will drop or even worse, and it will take time to recover! You know what they say, if its not broken, do not fix it!
you can be sure that when you change it you will get a hit. Think about it this way, is the perma link going to help you or your visitor. Does it really has to change or is it just aesthetics. Don't do it.
How many categories are we talking? Its pretty trivial to 301 a few things to strip out /category and or this will totally help as well.. https://wordpress.org/plugins/redirection/