There are different types of redirects that can be performed by a URL shortening service. These are named according to the uniform code that’s communicated to the browser, telling the browser what’s happening as the redirect occurs. There are seven standardized types but only two types are most often used.
Each of these redirects perform basically the same thing: Sending the visitor from one location to another automatically. Visitor requests page A. Page A contains instructions telling the visitor’s browser to instantly go to page B.
The critical difference between the two has to do with two things:
- The ability to modify the target URL
In the case of the 301 Redirect, there shouldn’t be an intent that the case should ever change. This might be something you’d do with a page that had been indexed by search engines but now must be retired forever. The 301 code tells browsers to go to the new destination the next time the old URL is requested. This would not be good for a URL shortening service that’s counting clicks – successive clicks after the first one wouldn’t be counted. 301 Redirects are the best in terms of SEO towards the target URL.
In the case of the 302 Redirect, you’ve got long term flexibility. With a shortened URL the 302 code tells browsers to “come back through next time” the shortened URL is requested instead of going straight to target page on subsequent clicks. This is good for tracking and analytics. This also allows producers and publishers to “get things wrong” once in a while and be able to change the target URL for an already published shortened URL – even after the links are indexed by search engines.
There are some liabilities with a 302 Redirect. These liabilities include link hijacking and that the shortened URL may end up appearing in the same search results as the target page. With link hijacking, something could cause the shortening service to change the target URL that the short URL points to. This could be out of malice or unintentional, but the bottom line would be a negative impact on the ability for visitors to get where they’re intended to go.