JavaScript Navigator activeVRDisplays Property

What You’ll Learn

navigator.activeVRDisplays comes from the old WebVR API. It returns every VRDisplay that is currently presenting. Learn what it returned, why it is deprecated, how to feature-detect it safely, and what to use instead with WebXR.

Introduction

The browser’s navigator object exposes information about the user agent and device capabilities. Years ago, WebVR added VR helpers on Navigator, including activeVRDisplays.

That property answered a simple question: which VR headsets are presenting right now? Only displays with VRDisplay.isPresenting === true appeared in the array.

This tutorial stays beginner-friendly: every example feature-detects first, so demos still make sense on laptops without a headset.

Understanding the activeVRDisplays Property

When supported, reading navigator.activeVRDisplays gives you an array of VRDisplay objects that are actively presenting immersive content.

• It is read-only — you inspect, you do not assign.
• An empty array means nothing is presenting (or you checked when VR was idle).
• Missing property means the browser does not expose legacy WebVR here.
• Requires a secure context (HTTPS / localhost) where it still exists.

📝 Syntax

General form of the property:

navigator.activeVRDisplays

Value

• An array of VRDisplay objects currently presenting.
• Often empty when no headset is in a presenting session.

Common patterns

// Always feature-detect first
if ("activeVRDisplays" in navigator) {
  const displays = navigator.activeVRDisplays;
  for (const display of displays) {
    console.log("Display " + display.displayId + " is active.");
  }
} else {
  console.log("WebVR activeVRDisplays is not available.");
}

// Prefer WebXR for new work
if (navigator.xr) {
  // Use navigator.xr.isSessionSupported / requestSession
}

Examples Gallery

Examples follow MDN Navigator.activeVRDisplays patterns, plus safe detection and WebXR guidance. Use View Output or Try It Yourself for each case.

const supported = "activeVRDisplays" in navigator;
console.log(supported ? "activeVRDisplays available" : "activeVRDisplays missing");
// Typical modern desktop: activeVRDisplays missing

activeVRDisplays missing
(or "available" on a rare legacy WebVR browser)

function showActive() {
  if (!("activeVRDisplays" in navigator)) {
    console.log("WebVR activeVRDisplays not supported");
    return;
  }
  const displays = navigator.activeVRDisplays;
  if (!displays.length) {
    console.log("No presenting VR displays");
    return;
  }
  for (const display of displays) {
    console.log("Display " + display.displayId + " is active.");
  }
}

showActive();

WebVR activeVRDisplays not supported
(or "No presenting VR displays" when supported but idle)

function getActiveCount() {
  if (!("activeVRDisplays" in navigator)) return -1; // not supported
  return navigator.activeVRDisplays.length;
}

const n = getActiveCount();
if (n < 0) console.log("not supported");
else if (n === 0) console.log("supported, none presenting");
else console.log(n + " display(s) presenting");

not supported

const lines = [];
lines.push("isSecureContext: " + window.isSecureContext);
lines.push(
  "activeVRDisplays: " +
    ("activeVRDisplays" in navigator ? "present" : "absent")
);
console.log(lines.join("\n"));

isSecureContext: true
activeVRDisplays: absent
(exact lines depend on your browser / page URL)

function describeVrApis() {
  if (navigator.xr) {
    return "Use WebXR via navigator.xr (recommended)";
  }
  if ("activeVRDisplays" in navigator) {
    return "Only legacy WebVR activeVRDisplays found";
  }
  return "No WebXR or WebVR entry points detected";
}

console.log(describeVrApis());

Use WebXR via navigator.xr (recommended)
(or "No WebXR or WebVR…" on some browsers / contexts)

🚀 Common Use Cases

• Legacy WebVR apps — see which displays are already presenting.
• Migration audits — find old activeVRDisplays usage to replace with WebXR.
• Feature detection education — practice safe in checks on Navigator.
• Not for new VR products — build on WebXR or a maintained 3D framework.
• Interview / history — know WebVR existed and was replaced.

📝 Notes

• Deprecated and non-standard — avoid in production.
• Secure context required where the property still exists.
• Superseded by the WebXR Device API (navigator.xr).
• Empty array ≠ missing API — feature-detect separately.
• Related learning: appCodeName, Window, EventTarget, JavaScript hub.

💡 Best Practices