JavaScript MediaStream getAudioTracks() Method

What You’ll Learn

The getAudioTracks() method of MediaStream returns an array of audio MediaStreamTrack objects in the stream. Learn the MDN getUserMedia timer example that stops the mic, empty arrays for video-only streams, filtering with track.kind, and comparison with getTracks()—with five examples and try-it labs.

Introduction

A MediaStream can hold both audio and video tracks. When you call getUserMedia({ audio: true, video: true }), the browser usually adds at least one microphone track and one camera track. getAudioTracks() gives you only the audio ones—handy for muting, stopping, or inspecting the mic without touching video.

MDN: the return value is an array where each entry is a MediaStreamTrack with kind === "audio". If there are no audio tracks, you get an empty array []. The order of tracks is not guaranteed and may change between calls.

Understanding MediaStream.getAudioTracks()

An instance method that filters the stream’s track set to audio tracks only.

• Parameters — none.
• Return value — array of MediaStreamTrack with kind "audio".
• Empty array — when the stream has no audio tracks (e.g. canvas video only).
• Order — not defined by the spec; may vary between calls (MDN).
• Pair with — getVideoTracks() for camera/screen video tracks.
• Baseline Widely available on MDN (since September 2017).

📝 Syntax

getAudioTracks()

Parameters

None.

Return value

An array of MediaStreamTrack objects for audio tracks. Empty if none exist.

Typical pattern (MDN idea)

navigator.mediaDevices
  .getUserMedia({ audio: true, video: true })
  .then((mediaStream) => {
    document.querySelector("video").srcObject = mediaStream;
    setTimeout(() => {
      const tracks = mediaStream.getAudioTracks();
      tracks[0].stop();
    }, 5000);
  });

⚖️ getAudioTracks() vs Related Ideas

Examples Gallery

Examples follow MDN MediaStream: getAudioTracks(). Mic examples use getUserMedia (secure context + permission); video-only demos use canvas.captureStream().

navigator.mediaDevices
  .getUserMedia({ audio: true, video: true })
  .then((mediaStream) => {
    document.querySelector("video").srcObject = mediaStream;
    setTimeout(() => {
      const tracks = mediaStream.getAudioTracks();
      if (tracks[0]) tracks[0].stop();
    }, 5000);
  });

After 5s: microphone track stopped
video may continue

navigator.mediaDevices
  .getUserMedia({ audio: true, video: false })
  .then((stream) => {
    const audioTracks = stream.getAudioTracks();
    console.log(audioTracks.length, audioTracks[0].kind);
  });

1 audio

const canvas = document.createElement("canvas");
const stream = canvas.captureStream();

const audio = stream.getAudioTracks();
const video = stream.getVideoTracks();

console.log(audio.length, video.length);

0 1

navigator.mediaDevices
  .getUserMedia({ audio: true, video: true })
  .then((stream) => {
    const direct = stream.getAudioTracks();
    const filtered = stream.getTracks().filter((t) => t.kind === "audio");
    console.log(direct.length, filtered.length);
  });

1 1

function muteAudio(stream) {
  stream.getAudioTracks().forEach((track) => {
    track.enabled = false;
  });
}

navigator.mediaDevices
  .getUserMedia({ audio: true })
  .then((stream) => {
    muteAudio(stream);
    console.log(stream.getAudioTracks()[0].enabled);
  });

false

🚀 Common Use Cases

• Stop the microphone while keeping the camera running (MDN timer pattern).
• Build a mute button that toggles track.enabled on audio tracks.
• Count how many audio inputs are in a composed stream.
• Route only audio tracks to an analyser or recorder.
• Verify a stream has audio before attaching to Web Audio API.

🔧 How It Works

📝 Notes

• MDN: Baseline Widely available (since September 2017) — no Deprecated / Experimental / Non-standard banner.
• Order not defined — do not rely on [0] being the same track every call without checking id or label.
• Secure context — getUserMedia examples need HTTPS or localhost.
• Empty array — normal for video-only or empty streams.
• Related learning: getVideoTracks(), addTrack(), active, getUserMedia().

💡 Best Practices