No, it’s not just you. As of Tuesday evening Pacific Time, YouTube was down for many users. The outage appears to have begun some time between 6 and 7 p.m., making this a pretty long outage for such a major site.
The company is well aware of the issue and tweeting its updates.
YouTube doesn’t experience downtime very often, making Tuesday’s outage pretty notable. We’ve reached out to YouTube about the cause of the outage and will update this story when we learn more.