How do I get the referrer URL in an ASP.NET MVC action?

How do I get the referrer URL in an ASP.NET MVC action? I am trying to redirect back to the page before you called an action.

How does MVC handle wrong URL?

First: Add a route pattern to the end of your routing table that matches to any URL. Second: Set the default controller and action values for this pattern to the controller/action method that will display the "more helpful" View you want to provide. (And, I guess, a third step: Provide that controller/action/View.)

Why is HTTP referer empty?

There might be several reasons why the referer URL would be blank. It will/may be empty when the enduser: entered the site URL in browser address bar itself. visited the site by a browser-maintained bookmark.

You can use Request.UrlReferrer to get the referring URL as well if you don't like accessing the Request.ServerVariables dictionary directly.