How to enable external request in IIS Express?

There are three changes you might need to make.

1. Tell IIS Express itself to bind to all ip addresses and hostnames. In your .config file. Typically:
   • VS 2015: $(solutionDir)\.vs\config\applicationhost.config
   • < VS 2015: %userprofile%\My Documents\IISExpress\config\applicationhost.config

Find your site's binding element, and add

    <binding protocol="http" bindingInformation="*:8080:*" />

2. Setup the bit of Windows called 'http.sys'. As an administrator, run the command:

    netsh http add urlacl url=http://*:8080/ user=everyone

Where everyone is a windows group. Use double quotes for groups with spaces like "Tout le monde".

3. Allow IIS Express through Windows firewall.

   Start / Windows Firewall with Advanced Security / Inbound Rules / New Rule...

   Program %ProgramFiles%\IIS Express\iisexpress.exe
   OR Port 8080 TCP

Now when you start iisexpress.exe you should see a message such as

Successfully registered URL "http://*:8080/" for site "hello world" application "/"

There's a blog post up on the IIS team site now explaining how to enable remote connections on IIS Express. Here is the pertinent part of that post summarized:

On Vista and Win7, run the following command from an administrative prompt:

netsh http add urlacl url=http://vaidesg:8080/ user=everyone

For XP, first install Windows XP Service Pack 2 Support Tools. Then run the following command from an administrative prompt:

httpcfg set urlacl /u http://vaidesg1:8080/ /a D:(A;;GX;;;WD)

Nothing worked for me until I found iisexpress-proxy.

Open command prompt as administrator, then run

npm install -g iisexpress-proxy

then

iisexpress-proxy 51123 to 81

assuming your Visual Studio project opens on localhost:51123 and you want to access on external IP address x.x.x.x:81

Edit: I am currently using ngrok