Can you play free games online with out an account

You would have to be more specific as to which gmes you are talking about; however, certain games are desined for the purpose of play without an account and others, the oposite.
It is generally mentioned if you need an account to play a free game online.
If you are talking about games hosted b sites such as "www.miniclip.com" or www.adictinggames.com, it is optional to create and use an account in order to play.
However, if you are talking about other browser games such Runescape or Adventurequest, or even other game programs that you buy in shops, it is mentioned that you definitely need an account in order to play these online.