The XRSession interface's onsqueezestart event handler property can be set to a function which is then invoked to handle the squeezestart event that's sent when the user successfully begins a primary squeeze action on a WebXR input device. These actions represent the user squeezing or tightly gripping an object or controller.

To learn more about how to use and handle WebXR controller inputs, see Inputs and input sources.


xrSession.onsqueezestart = squeezestartHandlerFunction;


A function to be invoked whenever the XRSession receives a squeezestart event.


This snippet of code adds a simple handler for the squeezestart event, which responds only to events on the user's dominant hand by getting the target ray, then calling a function findObjectUsingRay() to identify the object that the user is pointing at. This object is then stored in a heldObject variable in the user object we're using to represent user information.

xrSession.onsqueezestart = event => {
  if (event.inputSource.handedness == user.handedness) {
    let targetRayPose = event.frame.getPose(event.inputSource.targetRaySpace, myRefSpace;

    if (targetRayPose) {
      user.heldObject = findObjectUsingRay(targetRayPose.transform);


WebXR Device API
# dom-xrsession-onsqueezestart

Browser compatibility

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See also