Goal-line technology is a technical means of instantly determining whether the whole of the ball has crossed the goal line.

The International Football Association Board requires that goal-line technology (GLT) does not interfere with the game. As a consequence the requirements were set up to determine that only the match officials are to receive a signal to indicate whether or not the entire ball has crossed the line.

The information is transmitted within one second which ensures an immediate response from the referee. Due to this design there are no stoppages or other forms of interference in the game. The match officials are the only ones to receive the signal on their watches. Unless there is a conscious choice by the competition organiser to show a replay, the information is only available to the referee and helps in challenging situations.