The read-only sdpMLineIndex property on the RTCIceCandidate interface is a zero-based index of the m-line describing the media associated with the candidate.

This value is specified when creating the RTCIceCandidate by setting the corresponding sdpMLineIndex value in the RTCIceCandidateInit object when creating a new candidate with new RTCIceCandidate().

If you instead call RTCIceCandidate() with a string parameter containing the candidate m-line text, the value of sdpMLineIndex is extracted from the m-line.


var sdpMLineIndex = RTCIceCandidate.sdpMLineIndex;


A number containing a 0-based index into the set of m-lines providing media descriptions, indicating which media source is associated with the candidate, nor null if no such association is available.

Note: Attempting to add a candidate (using addIceCandidate()) that has a value of null for either sdpMid or sdpMLineIndex will throw a TypeError exception.




Specification Status Comment
WebRTC 1.0: Real-time Communication Between Browsers
The definition of 'RTCIceCandidate.sdpMLineIndex' in that specification.
Candidate Recommendation Initial definition.

Browser compatibility

FeatureChromeEdgeFirefoxInternet ExplorerOperaSafari
Basic support Yes1522 ? Yes ?
FeatureAndroid webviewChrome for AndroidEdge mobileFirefox for AndroidOpera AndroidiOS SafariSamsung Internet
Basic support Yes Yes Yes ? Yes ? Yes

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