How can I get my webapp's base URL in ASP.NET MVC?

How can I quickly determine what the root URL is for my ASP.NET MVC application? I.e., if IIS is set to serve my application at http://example.com/foo/bar, then I'd like to be able to get that URL in a reliable way that doesn't involve getting the current URL from the request and chopping it up in some fragile way that breaks if I re-route my action.

The reason that I need the base URL is that this web application calls another one that needs the root to the caller web application for callback purposes.

Assuming you have a Request object available, you can use:

string.Format("{0}://{1}{2}", Request.Url.Scheme, Request.Url.Authority, Url.Content("~"));

If it's not available, you can get to it via the context:

var request = HttpContext.Current.Request

So none of the ones listed here worked for me, but using a few of the answers, I got something working:

public string GetBaseUrl()
{
    var request = HttpContext.Current.Request;
    var appUrl = HttpRuntime.AppDomainAppVirtualPath;

    if (appUrl != "/") 
        appUrl = "/" + appUrl;

    var baseUrl = string.Format("{0}://{1}{2}", request.Url.Scheme, request.Url.Authority, appUrl);
        
    return baseUrl;
}

Update for ASP.NET Core / MVC 6:

ASP.NET Core makes this process a bit more painful, especially if you are deep in your code. You have 2 options to get at the HttpContext

1. Pass it in from your controller:

   var model = new MyClass(HttpContext);

then in model:

private HttpContext currentContext;

public MyClass(HttpContext currentContext)
{
    this.currentContext = currentContext;
}

2) Perhaps the cleaner way is to inject it into your class, which starts with registering the types in your Startup:

public void ConfigureServices(IServiceCollection services)
{
    // Add framework services.
    services.AddMvc();

    services.AddTransient<MyClass, MyClass>();
    services.TryAddSingleton<IHttpContextAccessor, HttpContextAccessor>();
}

then have it injected for you like this:

private HttpContext currentContext;

public MyClass(IHttpContextAccessor httpContextAccessor)
{
    currentContext = httpContextAccessor.HttpContext;
}

in either case, here is the updated for .NET Core GetBaseUrl():

public string GetBaseUrl()
{
    var request = currentContext.Request;
        
    var host = request.Host.ToUriComponent();

    var pathBase = request.PathBase.ToUriComponent();

    return $"{request.Scheme}://{host}{pathBase}";
}

In Code:

Url.Content("~/");

MVC3 Razor Syntax:

@Url.Content("~/")

Maybe it is extension or modification of the answers posted here but I use simply the following line and it works:

Request.Url.GetLeftPart(UriPartial.Authority) + Url.Content("~")

When my path is: http://host/iis_foldername/controller/action
then I receive : http://host/iis_foldername/

The following snippet works nicely for me in MVC4, and doesn't need an HttpContext available:

System.Web.HttpRuntime.AppDomainAppVirtualPath

The trick with relying upon IIS is that IIS bindings can be different from your public URLs (WCF I'm looking at you), especially with multi-homed production machines. I tend to vector toward using configuration to explicitly define the "base" url for external purposes as that tends to be a bit more successful than extracting it from the Request object.

For an absolute base URL use this. Works with both HTTP and HTTPS.

new Uri(Request.Url, Url.Content("~"))

This is a conversion of an asp.net property to MVC . It's a pretty much all singing all dancing get root url method.

Declare a helper class:

namespace MyTestProject.Helpers
{
    using System.Web;

    public static class PathHelper
    {
        public static string FullyQualifiedApplicationPath(HttpRequestBase httpRequestBase)
        {
            string appPath = string.Empty;

            if (httpRequestBase != null)
            {
                //Formatting the fully qualified website url/name
                appPath = string.Format("{0}://{1}{2}{3}",
                            httpRequestBase.Url.Scheme,
                            httpRequestBase.Url.Host,
                            httpRequestBase.Url.Port == 80 ? string.Empty : ":" + httpRequestBase.Url.Port,
                            httpRequestBase.ApplicationPath);
            }

            if (!appPath.EndsWith("/"))
            {
                appPath += "/";
            }

            return appPath;
        }
    }
}

Usage:

To use from a controller:

PathHelper.FullyQualifiedApplicationPath(ControllerContext.RequestContext.HttpContext.Request)

To use in a view:

@using MyTestProject.Helpers

PathHelper.FullyQualifiedApplicationPath(Request)

In MVC _Layout.cshtml:

<base href="@Request.GetBaseUrl()" />

Thats what we use!

public static class ExtensionMethods
{
public static string GetBaseUrl(this HttpRequestBase request)
        {
          if (request.Url == (Uri) null)
            return string.Empty;
          else
            return request.Url.Scheme + "://" + request.Url.Authority + VirtualPathUtility.ToAbsolute("~/");
        }
}

This works fine for me (also with a load balancer):

@{
    var urlHelper = new UrlHelper(Html.ViewContext.RequestContext);
    var baseurl = urlHelper.Content(“~”);
}

<script>
    var base_url = "@baseurl";
</script>

Especially if you are using non-standard port numbers, using Request.Url.Authority appears like a good lead at first, but fails in a LB environment.

You could have a static method that looks at HttpContext.Current and decides which URL to use (development or live server) depending on the host ID. HttpContext might even offer some easier way to do it, but this is the first option I found and it works fine.

You can use the following script in view:

<script type="text/javascript">
    var BASE_URL = '<%= ResolveUrl("~/") %>';
</script>

For ASP.NET MVC 4 it is a bit different:

string url = HttpContext.Request.Url.AbsoluteUri;

This is working in ASP .NET MVC 4 In any controller action you can write: 1stline gets the whole url+Query String. 2nd line remove local path & query ,last '/' symbol. 3rd line add '/' symbol at last position.

Uri url = System.Web.HttpContext.Current.Request.Url;
string UrlLink = url.OriginalString.Replace(url.PathAndQuery,"");
UrlLink = String.Concat(UrlLink,"/" );

in simple html and ASP.NET or ASP.NET MVC if you are using tag:

<a href="~/#about">About us</a>

On the webpage itself:

<input type="hidden" id="basePath" value="@string.Format("{0}://{1}{2}",
  HttpContext.Current.Request.Url.Scheme,
  HttpContext.Current.Request.Url.Authority,
  Url.Content("~"))" />

In the javascript:

function getReportFormGeneratorPath() {
  var formPath = $('#reportForm').attr('action');
  var newPath = $("#basePath").val() + formPath;
  return newPath;
}
        

This works for my MVC project, hope it helps

For url with aplication alias like http://example.com/appAlias/... You can try this:

var req = HttpContext.Current.Request;
string baseUrl = string.Format("{0}://{1}/{2}", req.Url.Scheme, req.Url.Authority, req.ApplicationPath);

This was my solution (using .net core 3.1, in an api controller):

string baseUrl = $"{Request.Scheme}://{Request.Headers.Where(h => h.Key == "Host").First().Value}";

For MVC 4:

String.Format("{0}://{1}{2}", Url.Request.RequestUri.Scheme, Url.Request.RequestUri.Authority, ControllerContext.Configuration.VirtualPathRoot);

Maybe it is a better solution.

@{
   var baseUrl = @Request.Host("/");
}

using

<a href="@baseUrl" class="link">Base URL</a>

I put this in the head of my _Layout.cshtml

 <base href="~/" />

@{
    var baseurl = Request.Url.Scheme + "://" + Request.Url.Host + ":" + Request.Url.Port + Url.Content("~");
}
@baseurl

--output http://localhost:49626/TEST/

In .net core 3.1 I used this approach:

$"{Request.Scheme}://{Request.Host}{Url.Content("~/")}"

The following worked solidly for me

var request = HttpContext.Request;
                        var appUrl = System.Web.HttpRuntime.AppDomainAppVirtualPath;

                        if (appUrl != "/")
                            appUrl = "/" + appUrl + "/";

                        var newUrl = string.Format("{0}://{1}{2}{3}/{4}", request.Url.Scheme, request.UrlReferrer.Host, appUrl, "Controller", "Action");

Also you can use this. For the razor pages, it is better to use it than the others.

https://ml-software.ch/posts/getting-the-base-url-for-an-asp-net-core-mvc-web-application-in-your-static-javascript-files

<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8" />
    <base href='@Url.AbsoluteContent("~/")'>
    <title>@ViewBag.Title - ASP.NET Core Web Application</title>
    <!-- ... -->
</head>
<body>

add this function in static class in project like utility class:

utility.cs content:

public static class Utility
{
    public static string GetBaseUrl()
    {
        var request = HttpContext.Current.Request;
        var urlHelper = new UrlHelper(request.RequestContext);
        var baseUrl = $"{request.Url.Scheme}://{request.Url.Authority}{urlHelper.Content("~")}";
        return baseUrl;
    }
}

use this code any where and enjoy it:

var baseUrl = Utility.GetBaseUrl();

Simply in one line get BaseUrl

string baseUrl = new Uri(Request.Url, Url.Content("~")).AbsoluteUri;

//output example: https://stackoverflow.com