The sliCount property of the RTCRtpStreamStats dictionary indicates how many Slice Loss Indication (SLI) packets were received by the sender. An SLI packet is used by a decoder to let the encoder know that it's detected corruption of one or more consecutive macroblocks in the received media.


var sliCount = RTCRtpStreamStats.sliCount;


An unsigned long integer indicating the number of SLI packets the sender received from the receiver due to lost runs of macroblocks. A high value of sliCount may be an indication of an unreliable network.

For technical details, see RFC 4585: 6.3.2.

Note: This value is sent by the sender to the receiver and is only present for video media.


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

Browser compatibility

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ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
sliCountChrome No support NoEdge ? Firefox No support NoIE No support NoOpera No support NoSafari ? WebView Android No support NoChrome Android No support NoFirefox Android No support NoOpera Android No support NoSafari iOS ? Samsung Internet Android No support No


No support Ā 
No support
Compatibility unknown Ā 
Compatibility unknown

See also

  • RFC 4585: 6.3.2: Definition of "Slice Loss Indication" in the document Extended RTP Profile for Real-time Transport Control Protocol (RTCP)-Based Feedback (RTP/AVPF).