In the classic black‑and‑white symbol, the black side is yin and the white side is yang.

Quick Scoop

  • Yin is associated with darkness, coolness, rest, receptivity, and the traditionally “feminine” principle.
  • Yang is associated with light, warmth, action, movement, and the traditionally “masculine” principle.
  • In the taiji (yin‑yang) symbol, black = yin with a white dot inside, and white = yang with a black dot inside, showing that each always contains a seed of the other.

So if you’re looking at the symbol and wondering “which one is yin and which one is yang?”:
Black, dark, resting side = yin; white, bright, active side = yang.

TL;DR : Black half is yin, white half is yang, and both only make sense in balance with each other.

Information gathered from public forums or data available on the internet and portrayed here.