Is it down - United Kingdom can check if a website is down or is it just your PC that can not access it. There can be cases where your PC (or MAC, Laptop, Mobile, Netbook or whatever) is having network issues (ISP related) or the access to certain website is blocked on your machine. Idea is simple, you tell me the domain name and I will try and check it, if it opens at my machine then it is time for you to pick up phone and call you ISP or IT support. If I suggest you to shout at your ISP or IT support you will do so on your own risk.
This website can check for websites with time out errors, offline servers, dns errors, network issues, scheduled downtime, unscheduled down time and deleted domain names to list a few. When you enter the domain name or sub domain name you want to check and the server will try to open it from it's own location. I even support custom ports, so if you want to check if your Web (80) / MySQL (3306) / CPanel & WHM (2082) / Telnet (23) / SSH (22) or Webmail (2095) or POP3/SMTP server (21 etc) or any other port is down just type it in like example.com:80.
This service is provided free of cost with no warranty of any kind.