files/en-us/web/api/mediatrackconstraints/volume/index.md
{{APIRef("Media Capture and Streams")}}{{Deprecated_Header}}{{Non-standard_Header}}
The {{domxref("MediaTrackConstraints")}} dictionary's
volume property is a ConstrainDouble
describing the requested or mandatory constraints placed upon the value of the
{{domxref("MediaTrackSettings.volume", "volume")}} constrainable property.
If needed, you can determine whether or not this constraint is supported by checking the value of {{domxref("MediaTrackSupportedConstraints.volume")}} as returned by a call to {{domxref("MediaDevices.getSupportedConstraints()")}}. However, typically this is unnecessary since browsers will ignore any constraints they're unfamiliar with.
A ConstrainDouble describing the acceptable or required value(s) for an
audio track's volume, on a linear scale where 0.0 means silence and 1.0 is the highest
supported volume.
If this value is a number, the user agent will attempt to obtain media whose volume is
as close as possible to this number given the capabilities of the hardware and the other
constraints specified. Otherwise, the value of this ConstrainDouble will
guide the user agent in its efforts to provide an exact match to the required volume (if
exact is specified or both min and max are
provided and have the same value) or to a best-possible value.
Any constraint set which only permits values outside the range 0.0 to 1.0 cannot be satisfied and will result in failure.
See the Constraint exerciser example.
{{Compat}}