How high must a table tennis player toss the ball during a legal serve?

A table tennis player must toss the ball at least 16 centimetres during a legal serve.

The server must begin with the ball resting freely on the open palm of the stationary free hand. The ball is then projected nearly vertically upward without imparting spin, and it must rise at least 16 centimetres before being struck. This requirement prevents a server from disguising the contact with a tiny hand-level release.

The ball must also remain behind the end line and above the playing surface during the serve. The server cannot hide the ball from the receiver with the body, arm, or clothing.

The 16-centimetre minimum is a toss height, not the height of the net. It is also not a requirement to throw the ball exactly 16 centimetres; higher tosses are permitted if the other service rules are followed.