How do you know if someone on YouTube is online?

Answer 1

It doesn't show you when someone else is online. But it does show the time they post a tweet.

Also; If you are a Tweetdeck user and happen to be online, prior to the time of the person you are wondering about, you can see them signing on if you are following them. They'll pop up. Usually in the right hand corner of Tweetdeck, which should be the factory setting.

Answer 2

No, you can't do that. It is possible to search for a particular member (by using the Community tab and then the search function), but there is no way to tell if they are online at any given time.

Answer 3

You will usually be able to tell if someone is online by looking under their avatar on that little bar. It usually says offline or online [which is shown with a yellow emote]. If they are on your friends list, go to that and if there is a yellow emote to the right of their username, they are online.
All of this works unless the user has changed their settings to appear offline.

Answer 4

you never really know but my best guess is if the were last signed in recently

Answer 5

There is no specific way to see if a user is online. You can, however, get some idea by looking at their recent tweets and checking the time of when they last tweeted.

Answer 6

You dont, its not like facebook, you can tweet them, follow them and direct message them but you dont know.