Just something I have been playing around with to showcase responsive design :)

Make sure it is not a https url :)

Hi Ellie,

I was aware it was not working for some urls but did not really know why,

however I found this article and it was a good read so best to share anything useful link

This is possibly why we are not seeing testing like this all over the web as it could turn out to be really buggy..

anyway thanks for looking

Craig

Ryan, would you happen to know why a url with https would not work :S its got me stumped ...

It's most likely due to a security issue. Through some testing, https://facebook.com and https://dropbox.com wouldn't display, and pulling up the console indicated these errors:

Refused to display 'https://www.facebook.com/?_rdr' in a frame because it set 'X-Frame-Options' to 'DENY'.

and

Refused to display 'https://www.dropbox.com/' in a frame because it set 'X-Frame-Options' to 'SAMEORIGIN'.

Which is basically them disallowing their sites to be shown in iframes on other servers. Another site, https://guildwars2.com does display, however, so it's nothing to do with your tool, just whether the destination site allows their content to be displayed in frames from another server.