I'm trying to find a reliable solution to determine if my page was loaded in iframe on external site using javascript.
If iframe src located on the same domain it's preaty easy: you can use if (window.frameElement) or if (window.location !== window.parent.location) but if iframe src is not on the same domain all modern browsers throw exception when accessing parent and even comparing it with null.
I'm totally lost.
You might be interested in the Coding Horror entry: We Done Been Framed. Offers an interesting technical discussion on this topic, including solutions, and frame-busting-busting.
You can wrap your validation (window.location !== window.parent.location / window.frameElement) in try-catch statement which you can use to handle the exception yourself.
Why don't you try a function with the following
var element = window.parent.document if (element) return "Is in a parent window" else "is not in a parent window";
