There are various ways to play Texas Hold em poker estrategias online for free. Places such as Global Poker, PokerStars Play, and the World Series of Poker all offer free ways to play the game of holdem.
PokerStars is first on the list. By toggling the Play Money option, you can try out all of their free online poker games without any investment. The interface will look the same, but there's no real money at play. You can still play Texas hold 'em, Omaha, and even short deck at the tables.