Do 301 Redirects Hurt SEO?

A 301 redirect is a function of a web server that allows for a web page (or other file) to change address. The 301 is the method used to communicate the page has "moved permanently.
"The term "301 redirect" is used because web servers send a status code with every request that communicate the results from that request.
You've probably encountered another type of status code situation while browsing the web that you'll be more familiar with: the 404 error page. You'll often encounter a 404 error page when you try to visit a page that doesn't exist. The "404" part is the status code that corresponds to a page "not found" error. So, when you try to visit a page that doesn't exist, a properly functioning web server will return a 404 status code.Likewise, 301 is the status code to communicate that a page was "moved permanently." In other words, it moved and it's not coming back (vs. a 302 status code that means it was a temporary move).So when people refer to a "301 redirect," they talking about a page that is permanently moving. After the page has moved, in most cases, the developer needs to go in and add a 301 redirect so that, when someone tries to visit the old URL, they get redirected automatically to the new URL.The 301 code (vs. a 302 code) also tells search engines, "Hey, this page has moved permanently, here's the new address, update your records." Assuming the new URL is found, the search engines will update the page that is showing up in search results to the new address.So you're solving 2 major problems with a 301:
Implementing a few 301 redirects alone, if done correctly, will not have a negative impact on SEO. However, there is the potential for 301s to hurt SEO because of some side effects of using 301s:
If a small number of pages are moving and you properly implement a 301 redirect, then you shouldn't notice any impact from that change.Where people get in trouble is when they change something. For example, if you move a page AND change it's content, then yes you run the risk of that page dropping in search. But the problem isn't the redirect in that case, it's the fact that you changed the content.It's not advisable to move content and change it at the same time. It makes diagnosing problems difficult and extremely time consuming.
This is where people get into trouble. When people redesign a site, they often make pretty big content changes IN ADDITION TO changing URLs.This is always extremely risky. And yes, I'm aware that this is the most common approach to redesigning a website, but that's also why it's sort of become common knowledge that search traffic drops after a redesign, usually with the hope that it recovers, possibly higher than before. But that's not necessary at all. Traffic drops are completely preventable.This is because when a redesign happens, most people end up changing everything, including:
All 3 of those items can impact SEO. So by changing everything all at once, you've done 2 things:
I also realize that doing all this at once is, by far, the dominant approach to redesigning a website. This article alone isn't going to change that.The solution is to ensure your budget includes the cost to have someone well-versed in this sort of thing consult on the project. It's not cheap, but very few web design companies (even those with SEO on the services list) will include this in their scope.The cost of inadequate planning can be catastrophic. I consulted on a project after a new site was launched that resulted in a 60% drop in lead flow overnight. Fixing the problem only brought back a small % of that lost lead flow. So if your site relies on SEO for a good chunk of business, it might be expensive, but you should definitely budget for proper planning / mitigation work, OR just don't change everything at once.