Server.Transfer Vs. Response.Redirect

Question

What is difference between Server.Transfer and Response.Redirect?

• What are advantages and disadvantages of each?
• When is one

Answer 1

Response.Redirect Response.Redirect() will send you to a new page, update the address bar and add it to the Browser History. On your browser you can click back. It redirects the request to some plain HTML pages on our server or to some other web server. It causes additional roundtrips to the server on each request. It doesn’t preserve Query String and Form Variables from the original request. It enables to see the new redirected URL where it is redirected in the browser (and be able to bookmark it if it’s necessary). Response. Redirect simply sends a message down to the (HTTP 302) browser.

Server.Transfer Server.Transfer() does not change the address bar, we cannot hit back.One should use Server.Transfer() when he/she doesn’t want the user to see where he is going. Sometime on a "loading" type page. It transfers current page request to another .aspx page on the same server. It preserves server resources and avoids the unnecessary roundtrips to the server. It preserves Query String and Form Variables (optionally). It doesn’t show the real URL where it redirects the request in the users Web Browser. Server.Transfer happens without the browser knowing anything, the browser request a page, but the server returns the content of another.

Answer 2

Server.Transfer doesn't change the URL in the client browser, so effectively the browser does not know you changed to another server-side handler. Response.Redirect tells the browser to move to a different page, so the url in the titlebar changes.

Server.Transfer is slightly faster since it avoids one roundtrip to the server, but the non-change of url may be either good or bad for you, depending on what you're trying to do.

Answer 3

To be Short: Response.Redirect simply tells the browser to visit another page. Server.Transfer helps reduce server requests, keeps the URL the same and, with a little bug-bashing, allows you to transfer the query string and form variables.

Something I found and agree with (source):

Server.Transfer is similar in that it sends the user to another page with a statement such as Server.Transfer("WebForm2.aspx"). However, the statement has a number of distinct advantages and disadvantages.

Firstly, transferring to another page using Server.Transfer conserves server resources. Instead of telling the browser to redirect, it simply changes the "focus" on the Web server and transfers the request. This means you don't get quite as many HTTP requests coming through, which therefore eases the pressure on your Web server and makes your applications run faster.

But watch out: because the "transfer" process can work on only those sites running on the server; you can't use Server.Transfer to send the user to an external site. Only Response.Redirect can do that.

Secondly, Server.Transfer maintains the original URL in the browser. This can really help streamline data entry techniques, although it may make for confusion when debugging.

That's not all: The Server.Transfer method also has a second parameter—"preserveForm". If you set this to True, using a statement such as Server.Transfer("WebForm2.aspx", True), the existing query string and any form variables will still be available to the page you are transferring to.

For example, if your WebForm1.aspx has a TextBox control called TextBox1 and you transferred to WebForm2.aspx with the preserveForm parameter set to True, you'd be able to retrieve the value of the original page TextBox control by referencing Request.Form("TextBox1").

Answer 4

Response.Redirect is more costly since it adds an extra trip to the server to figure out where to go.

Server.Transfer is more efficient however it can be a little mis-leading to the user since the Url doesn't physically change.

In my experience, the difference in performance has not been significant enough to use the latter approach

Answer 5

Response.Redirect() will send you to a new page, update the address bar and add it to the Browser History. On your browser you can click back.

Server.Transfer() does not change the address bar. You cannot hit back.

I use Server.Transfer() when I don't want the user to see where I am going. Sometimes on a "loading" type page.

Otherwise I'll always use Response.Redirect().

Answer 6

Just more details about Transfer(), it's actually is Server.Execute() + Response.End(), its source code is below (from Mono/.net 4.0):

public void Transfer (string path, bool preserveForm)
{
    this.Execute (path, null, preserveForm, true);
    this.context.Response.End ();
}

and for Execute(), what it is to run is the handler of the given path, see

ASP.NET does not verify that the current user is authorized to view the resource delivered by the Execute method. Although the ASP.NET authorization and authentication logic runs before the original resource handler is called, ASP.NET directly calls the handler indicated by the Execute method and does not rerun authentication and authorization logic for the new resource. If your application's security policy requires clients to have appropriate authorization to access the resource, the application should force reauthorization or provide a custom access-control mechanism.

You can force reauthorization by using the Redirect method instead of the Execute method. Redirect performs a client-side redirect in which the browser requests the new resource. Because this redirect is a new request entering the system, it is subjected to all the authentication and authorization logic of both Internet Information Services (IIS) and ASP.NET security policy.

-from MSDN