As a free app, Tinkercad wasn't originally built to bear such an awesome spike in use, so the time has come to strengthen it. We have seen such a massive increase in people coming to the site, that we needed to create new infrastructure to better support our users. While the site being down should only last a few days at most, we appreciate your understanding and your patience as the team works on getting Tinkercad back up to snuff!
We miss seeing the great models you've been making, and can’t wait to get you back online to tinker away. For more updates please check twitter.com/tinkercad