Since we are able to connect to validator.w3.org that usually indicates that there is something wrong with your internet. There is a small chance that we could be able to connect to W3 Validator , but there website will not load beyond that, but it is unlikely. You should try to connect to another large website like google or facebook. If you can't load those sites then it is likely that your internet is having and issue.You could also try connecting to one of their other sites, such as W3 Jigsaw If we were not able to connect that means you aren't the only one having a problem getting to validator.w3.org, and that the problem is not with your computer or your connection. The only thing you can do is wait for W3 Validator to resolve their problems. If you continue to have a problem for an extended period of time you might want to try to contact W3 Validator
It is a utility that constantly monitors some of the most popular sites on the internet to see when they are down. Often times it is hard to know if a site is actually down or not, or if it is only you that can't reach the site. If we are not able to reach the site, chances are that the website is having problems and it is not a problem on your end.