InputEvent.isComposing

The InputEvent.isComposing read-only property returns a Boolean value indicating if the event is fired after compositionstart (en-US) and before compositionend (en-US).

var bool = event.isComposing;

var inputEvent = new InputEvent("syntheticInput", false);
console.log(inputEvent.isComposing); // return false

• compositionstart (en-US) and compositionend (en-US)
• InputEvent