Is a site really down?

Is it down just for me?

Sometimes I have to know if one of my websites or one of a client is down or not. More than once I’ve been tricked by the ISP’s troubles that a site is down. I use my smartphone to doublecheck but I’ve found an even better sollution:

You just enter your problem site and they will tell you if your site is really down or is just your ISP fooling around.