An impact driver or impact tool includes a motor, a motor housing that houses the motor, a grip housing integrally provided with the motor housing, a hammer case is disposed frontward of the motor housing, a spindle rotated by the motor, a hammer housed inside the hammer case and configured to be rotated by the spindle, and an anvil housed inside the hammer case which anvil is configured to be impacted by the hammer. In this impact driver, a length from a rear end of the motor housing to a front end of the anvil (i.e., the front-rear length of a main body) is less than 128 mm.