Fortunately, in Penal Code Sec. 337j(e)(2)(D) we're told that games played with cards in a private home where no one profits from the running of the game are 100% fine. So yes, since online poker is played at home with the only gains being your winnings, it's perfectly legal.

Enter Freerolls At Real Money Sites and Play Without Paying\n\n You can start playing free online poker without depositing, but only on a few sites. The entry for freerolls is usually limited to a few thousand players. Out of all online poker sites, 888poker has one of the best freeroll schedules.