startline

Startline, often written as two words, start line or starting line, refers to the official marker at which a race or competition begins. It serves as the reference point for the start of timing and positioning. While most references use two words, some sources or branding contexts may use the single-word form "startline." In track and field and road racing, the start line is typically marked on the surface and may be a painted line, a banner, a tape, or a combination of markings and sensors.

Startline configurations vary by sport. A starter’s signal—such as a pistol, horn, or electronic tone—commonly marks the moment of the start, while in other formats the start is triggered when competitors cross a start line or start mat to enable precise timing. Some events employ rolling starts or staged starts to balance pacing, safety, and fairness. Modern timing systems often pair the start trigger with automatic timing to produce official results.

The startline also defines the course length and layout. In linear races, the distance from the start line to the finish line is measured along the course; in loop or circuit formats, laps begin at the start line. Precise marking is essential for accurate timing, fair competition, and safety, as errors at the start can affect all competitors.

In everyday use, startline is commonly synonymous with starting line and can be used metaphorically to denote the beginning of any undertaking or competition.