The activeCues read-only property of the TextTrack interface returns a TextTrackCueList object listing the currently active cues.

A TextTrackCueList object.

The following example adds a new TextTrack to a video. The activeCues are printed to the console.

let video = document.querySelector("video");
let track = video.addTextTrack("captions", "Captions", "en");
track.mode = "showing";
console.log(track.activeCues);