Ever try a website only to have it not load and wonder to yourself, “I wonder if this is down for everyone or if it is a problem with my network?”
http://downforeveryoneorjustme.com
Because sometimes connections drop, or your DNS is somehow holding onto a change, or you have some kind of cookie or session issue with a website, to the rescue is DownForEveryoneOrJustMe.com
The beauty of Down For Everyone Or Just Me is that it form a triangle: You are accessing DFEOJM, then DFEOJM pings the real website, and then DFEOJM responds to your request.
Most of the time, if you can actually access DFEOJM, your internet connection is working OK so, in theory, you should also be able to access the website you are trying to get to. But every now and then you run into a DNS resolution related bump (that means a problem getting your domain name or subdomain to be found on the internet DNS, which kind of like a global directory.)
This tool is like having “a friend on another network” who can test to see if the website down for them too.
Also, you might remember the attack on DynDNS on October 21, 2016, which had regional effects: people on providers in North America were unable to get DNS resolution on certain domains because of a DDOS (denial of service) attack on DynDNS, which in turn affected most websites across America. (In that example, it was an attack on the intermediary SSL certificates.) Nonetheless, if the domain is experiencing some kind of regional resolution failure as was seen on 10/21/2016, DFEOJM could be used to test DNS resolution remotely.