The nackCount property of the RTCRtpStreamStats dictionary is a numeric value indicating the number of times the receiver sent a NACK packet to the sender. A NACK (Negative ACKnowledgement, also called "Generic NACK") packet tells the sender that one or more of the RTP packets it sent were lost in transport.


var nackCount = RTCRtpStreamStats.nackCount;


An integer value indicating how many times the receiver sent a NACK packet to the sender after detecting that one or more packets were lost during transport.

Note: This value is only available on the receiver.


Specification Status Comment
Identifiers for WebRTC's Statistics API
The definition of 'RTCRtpStreamStats.nackCount' in that specification.
Candidate Recommendation Initial definition.

Browser compatibilityUpdate compatibility data on GitHub

Chrome Edge Firefox Internet Explorer Opera Safari
Basic support No ? 55 No No ?
Android webview Chrome for Android Edge Mobile Firefox for Android Opera for Android iOS Safari Samsung Internet
Basic support No No ? 55 No ? ?

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