Difference Between Response.Redirect() and Server.Transfer() Methods in ASP.Net

Response.Redirect("UserDetail.aspx");
Server.Transfer("UserDetail.aspx");

Figure 1.3 Request and Response using Server.Transfer method

Now Figure 1.3 explains that the first request goes to the web server and then gets a response so the round-trip is not made by the Server. Transfer method. You get the same page response but different content. That means your web page URL in the address bar will not be changed. For example, see Figure 1.3 shows you get the same page as the previous request page so the previous page still remains while in Response. Redirect you get a different page in the response (see Figure 1.1 ). That means the address bar URL will be changed in the Response. Redirect method and also updates the browser history so you can move back from the browser back button.

Figure 1.4 Server.Transfer method request and response

Response.Redirect can be used for both .aspx and HTML pages whereas Server.Transfer can be used only for .aspx pages and is specific to ASP and ASP.NET.

Response.Redirect can be used to redirect a user to an external websites. Server.Transfer can be used only on sites running on the same server. You cannot use Server.Transfer to redirect the user to a page running on a different server.

When you use Server.Transfer then the previous page also exists in server memory while in the Response.Redirect method the previous page is removed from server memory and loads a new page in memory. Let's see an example.

We add some items in the context of the first page "UserRegister.aspx" and thereafter the user transfers to another page "UserDetail.aspx" using Server.Transfer on a button click. The user will then be able to request data that was in the context because the previous page also exists in memory. Let's see the code.

Code of the UserRegister.aspx.cs page.

using System;
public partial class UserRegister : System.Web.UI.Page
{
    protected void btn_Detail_Click(object sender, EventArgs e)
    {
        Context.Items.Add("Name", "Sandeep Singh Shekhawat");
        Context.Items.Add("Email", "[email protected]");
        Server.Transfer("UserDetail.aspx");
    }
}

Code of the UserDetail.aspx.cs page.

using System;
public partial class UserDetail : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        try
        {
            Response.Write(string.Format("My name is {0} and email address is {1}",
                                          Context.Items["Name"].ToString(),
                                          Context.Items["Email"].ToString()));
        }
        catch (NullReferenceException ex)
        {
            Response.Write(ex.Message);
        }
    }
}

Using the code above we can get data from the previous page to the new page by the Context. Item collection. But if you use the Response. Redirect method then you can't get context data on another page and get an exception object as null because the previous page doesn't exist in server memory.

Figure 1.5 Null Exception by the Context object

Mostly the Server. Transfer method is preferable to use because of Server.Transfer is faster since there is one less roundtrip, but some people say that Server. Transfer is not recommended since the operations typically flow through several different pages causing a loss of the correct URL of the page, but again it all depends on your requirements.

It is not a complete list. I wrote the basic differences between these two. If you know more differences then please provide them in the comments.