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    A simple, yet practical command-line utility enabling .NET developers to test web applications served by IIS Express on remote devices.


    Are you a .NET developer building mobile web applications? Have you ever been frustrated by the fact that there's no easy way to enable IIS Express to accept connections from remote devices?...


    Most likely you'll want iisexpress-proxy installed as a global module:

    npm install -g iisexpress-proxy

    Note: You need to have Node.js installed.


    If you installed iisexpress-proxy as a global module:

    iisexpress-proxy localPort to proxyPort

    For instance, if your application's IIS Express port is 51123, run this in the Command Prompt:

    iisexpress-proxy 51123 to 3000

    The program will list the external addresses you can use for testing your application on remote devices.

    Advanced usage (VPN, virtual hosts, etc.)

    You can also use iisexpress-proxy to expose an IIS server instance running on a different host accessible through VPN, like this:

    iisexpress-proxy host:port to proxyPort

    For instance, let's conside this scenario:

    • the application is running on and it only accepts connections from clients within a VPN;
    • your development machine has a network interface within the same VPN and another publicly accessible one (;
    • you need to test the application from mobile devices without having to add those devices to the VPN.

    By running this in the Command Prompt:

    iisexpress-proxy to 3000
'll be able to access the application by pointing the mobile devices to

    Note: This functionality was added at v1.1.0 (released 10/21/2015).

    WebSocket support was added in v1.4.0 by Stan Hebben - see PR #11 for details.


    iisexpress-proxy doesn't work in scenarios involving integrated Windows authentication (see issue #here).

    How does it work

    It's proxying the HTTP traffic on localPort to proxyPort on all the available network interfaces and it's also changing the origin of the host header, allowing you to test web applications hosted by IIS Express on various remote devices (mobile devices, other desktops, etc.).

    If you need to access the original host requested by the browser, the request headers will include X-Forward headers. In ASP.NET, Request.Headers["x-forwarded-host"] will contain the requested host.

    Credits and attributions

    This command-line utility wraps http-proxy. The original http-proxy logo was created by Diego Pasquali.

    Endorsing the author

    If you find this repo useful, please give it a star, tweet about it and endorse me on LinkedIn:

    Ionut-Cristian Florescu on LinkedIn

    Before raising issues

    I'm getting lots of questions from people just learning to do web development or simply looking to solve a very specific problem they're dealing with. While I will answer some of them for the benefit of the community, please understand that open-source is a shared effort and it's definitely not about piggybacking on other people's work. On places like GitHub, that means raising issues is encouraged, but coming up with useful PRs is a lot better. If I'm willing to share some of my code for free, I'm doing it for a number of reasons: my own intellectual challenges, pride, arrogance, stubbornness to believe I'm bringing a contribution to common progress and freedom, etc. Your particular well-being is probably not one of those reasons. I'm not in the business of providing free consultancy, so if you need my help to solve your specific problem, there's a fee for that.


    The ISC License.


    npm i iisexpress-proxy

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