While on an intranet, how can I distinguish whether a website is available publicly or not?
I gave a link to someone and then realized that he could not access it because it was on the intranet. Is there some way to know?
a site similar to http://downforeveryoneorjustme.com/ should do the job.
If you mean a way to find if anouther intranet user can see a internet site, then it depends on firewall settings and similar. Thats a much bigger topic.
I usually use a proxy server such as https://www.hidemyass.com/proxy to test the accessibility of an internally hosted site.
That will access the url on the intranet from a site outside. If you can browse to it through that, then so can others.