This is an experimental technology
Because this technology's specification has not stabilized, check the compatibility table for usage in various browsers. Also note that the syntax and behavior of an experimental technology is subject to change in future versions of browsers as the specification changes.
The elapsedTime read-only property of the SpeechSynthesisUtterance interface returns the elapsed time in seconds after the SpeechSynthesisUtterance.text started being spoken that the event was triggered at.
Syntax
event.elapsedTime;
Value
A float.
Examples
utterThis.onboundary = function(event) {
  console.log(event.name + ' boundary reached after ' + event.elapsedTime + ' seconds.');
}
Specifications
| Specification | Status | Comment | 
|---|---|---|
| Web Speech API The definition of 'elapsedTime' in that specification. | Draft | 
Browser compatibility
| Feature | Chrome | Edge | Firefox (Gecko) | Internet Explorer | Opera | Safari (WebKit) | 
|---|---|---|---|---|---|---|
| Basic support | 33 | (Yes) | 49 (49) | No support | ? | 7 | 
| Feature | Android | Chrome | Edge | Firefox Mobile (Gecko) | Firefox OS | IE Phone | Opera Mobile | Safari Mobile | 
|---|---|---|---|---|---|---|---|---|
| Basic support | (Yes) | (Yes) | (Yes) | No support | 2.0 | No support | No support | 7.1 |