How to 301 redirect in ASP.NET

A 301 redirect tells search engines and browsers that the resource has been permanently moved to a new URL.

How to 301 redirect in ASP.NET?

In case you are in a class that does not have a Response object directly available, you can use HttpContext.Current to access the response:

HttpContext.Current.Response.StatusCode = 301;
HttpContext.Current.Response.Status = "301 Moved Permanently";
HttpContext.Current.Response.Redirect("https://www.newdomain.com/newpath", false);
HttpContext.Current.Response.End();

If you want to handle redirects globally, you can use the Application_BeginRequest event in Global.asax to check incoming URLs and perform a redirect:

For example, Using Application_BeginRequest in Global.asax

protected void Application_BeginRequest(object sender, EventArgs e)
{
    var context = HttpContext.Current;
    var requestUrl = context.Request.Url.AbsolutePath.ToLower();

    // Check if the old URL is being requested
    if (requestUrl == "/old-path")
    {
        // Set the status code for permanent redirect (301)
        context.Response.StatusCode = 301;
        context.Response.Status = "301 Moved Permanently";        
        // Perform the redirect
        context.Response.Redirect("https://www.newdomain.com/newpath", false);
        context.Response.End();
    }
}

You want a 301 redirect, you can also use context is the HttpContext

context.Response.Status = "301 Moved Permanently";
context.Response.StatusCode = 301;
context.Response.AppendHeader("Location", "https://www.newdomain.com/newpath");

How to Implement an HTTP 301 Permanent Redirect Route in ASP.NET MVC?

To implement an HTTP 301 Permanent Redirect route in an ASP.NET MVC application, you can use the Response.Redirect method.

In the controller where the old route exists, you can add an action that redirects to the new URL.

For example, Using Response.Redirect in Controller Actions

public class RedirectController : Controller
{
    public ActionResult OldUrl()
    {
        // Set the status code to 301 (permanent redirect)
        Response.StatusCode = 301;
        Response.Status = "301 Moved Permanently";
        
        // Redirect to the new URL
        return Redirect("https://www.newdomain.com/newpath", permanent: true);
    }
}

If you want to configure a specific route to trigger the redirect, you can define that route in RouteConfig.cs.

public class RouteConfig
{
    public static void RegisterRoutes(RouteCollection routes)
    {
        routes.MapRoute(
            name: "OldUrlRedirect",
            url: "old-url",
            defaults: new { controller = "Redirect", action = "OldUrl" }
        );

        // Other routes...
    }
}

In this example, when someone accesses /old-url, the request will be handled by the OldUrl action of the RedirectController, which will send the 301 permanent redirect to the new URL.

If you're using IIS 7 or higher, the simplest solution for implementing a 301 permanent redirect is to use the <httpRedirect> element in your web.config file. This method allows you to configure redirects directly within the server settings, without needing to modify application code.

<httpRedirect enabled="true" exactDestination="true" httpResponseStatus="Permanent">
     <add wildcard="/old.aspx" destination="/new.aspx" />
     <add wildcard="/old.html" destination="/new.aspx" />
</httpRedirect>

This method is very powerful, especially if you've changed the domain but the page structure remains the same. You can simply add the <httpRedirect> element in your web.config to automatically redirect all requests from the old domain to the new one, preserving the page paths without needing to specify individual redirects.

<system.webServer> 
    <httpRedirect enabled="true" childOnly="true" destination="http://www.mynewdomain.com/" /> 
</system.webServer>

You can also add a Rule to web.config

In your web.config file, you can set up a rewrite rule to handle the redirect:

<configuration>
  <system.webServer>
    <rewrite>
      <rules>
        <rule name="Redirect Old Path to New Path" stopProcessing="true">
          <match url="^old-path$" />
          <action type="Redirect" url="https://www.newdomain.com/newpath" redirectType="Permanent" />
        </rule>
      </rules>
    </rewrite>
  </system.webServer>
</configuration>

The match element checks for requests to /old-path.

The action element issues a permanent redirect (redirectType="Permanent").

This method does not require changes to the application code and can handle multiple redirects efficiently.

ASP.NET MVC supports attribute routing, where you can use attributes to configure routes for controllers and actions.

If you're using ASP.NET MVC 5 or later, you can combine attribute routing with redirects:

[Route("old-url")]
public ActionResult OldUrl()
{
    return RedirectPermanent("https://www.newdomain.com/newpath");
}

The [Route] attribute is used to map the old URL directly to this action.