Can a redirect (and then redirect back) to check to see if users are logged-in hurt SEO?

Question

I have a SaaS product which is hosted under several different domains. However, there is one company that manages all these domains. They asked for a system to be able to login at domain1.com and automatically be logged in at domain2.com etc. We implemented this feature using a central CAS server. However the solution requires a redirect (once only) to the CAS server domain to check if the user is logged in. Here is an example of the trace:

1. www.example.com text/html 301 - permanent redirect (without www)
2. example.com text/html 302 - temporary redirect (to check if user logged in via CAS server domain)
3. login.cas-server.com/login text/html 303 - redirect again since action is complete here
4. example.com text/html 200
5. ...rest of page resources loads all OK text/html 200

The problem we have noticed is that it appears traffic to the site has started to drop since we implemented this.

My question is does the above practice hurt SEO and if so is there a way to tell search engine bots that we need to perform this redirect first (and to ignore it)? Is another redirect code better to use (perhaps 307)?

Answer 1

I strongly recommend not to use these redirects just check the user is login or not. Let me explain what a 301 redirect will do:

When you use 301 redirect from page 1 to page 2, search engines will pass the value of all all page authority, rankings, and backlinks from page 1 to page 2. In this situation, page 1 will lose its rankings and page 2 will start gaining ranks as it was for page 1.

I am sure you can find some alternate solution of this redirection.

Answer 2

A 301 Moved Permanently is used to mark a page as having moved permanently. It should not be used to pass data back and forth between servers or services.