How to check with javascript if connection is local host?

I want to have a check in my javascript if the page loading up is on my local machine.

The reason why I want to do that is that when I developing I like to make sure that both my server side(C#) validation is working correctly. So I like to see both the client side and server sides errors to show up.

So while I am testing I have a flag in my jquery validate stuff that just always lets invalid data go through. This way I see the client side and server errors at one go.

However right now I have to manually go and change back and forth when going from development to production.

Solution 1:

The location.hostname variable gives you the current host. That should be enough for you to determine which environment you are in.

if (location.hostname === "localhost" || location.hostname === "127.0.0.1")
    alert("It's a local server!");

Solution 2:

if launching static html in browser, eg from location like file:///C:/Documents and Settings/Administrator/Desktop/ detecting "localhost" will not work. location.hostname will return empty string. so

if (location.hostname === "localhost" || location.hostname === "127.0.0.1" || location.hostname === "")
    alert("It's a local server!");