Scotland Under-21 midfielder Dale Carrick has signed until summer 2014, left-back Kevin McHattie - who has made 10 starts this season - signed a two-year deal, while Scotland Under-19 goalkeeper Jack Hamilton put pen to paper for another year.
Another Scotland Under-21 squad player, forward David Smith, has extended his loan spell with Raith for a month.
Hearts released youth player Ewan Saunderson after earlier freeing Danny Thomson, Michael Thomson and Callum Wylie, but the exits did not spark the arrival of any more players.
The club tweeted there was "no other transfer business scheduled for this evening, either in or out of the club".
Hearts are restricted to signing under-21 players on a one-in, one-out basis, and on less wages than the player departing, and this month brought in Danny Wilson and Michael Ngoo on loan from Liverpool.