RTCIceCandidate.candidate

The read-only property candidate on the RTCIceCandidate interface returns a DOMString describing the candidate in detail. Most of the other properties of RTCIceCandidate are actually extracted from this string.

This property can be configured by specifying the value of the candidate property when constructing the new candidate object using RTCIceCandidate().

Syntax

var candidate = RTCIceCandidate.candidate;

Value

A DOMString describing the properties of the candidate, taken directly from the SDP attribute "candidate". The candidate string specifies the network connectivity information for the candidate. If the candidate is an empty string (""), the end of the candidate list has been reached; this candidate is known as the "end-of-candidates marker."

The syntax of the candidate string is described in RFC 5245, section 15.1. For an a-line (attribute line) that looks like this:

a=candidate:4234997325 1 udp 2043278322 192.168.0.56 44323 typ host

the corresponding candidate string's value will be "candidate:4234997325 1 udp 2043278322 192.168.0.56 44323 typ host".

The user agent always prefers candidates with the highest priority, all else being equal. In the example above, the priority is 2043278322. The attributes are all separated by a single space character, and are in a specific order. The complete list of attributes for this example candidate is:

Example

In this example, we see a function which receives as input an SDP string containing an ICE candidate received from the remote peer during the signaling process.

function handleNewIceCandidate(candidateSDP) {
  var candidateObj = new RTCIceCandidate(candidateSDP);

  myPeerConnection.addIceCandidate(candidateObj).catch({
    /* handle the error thrown by addIceCandidate() */
  });
}

The handleNewIceCandidate() function shown here passes the received candidate's SDP text into RTCIceCandidate() to receive an RTCIceCanddiate object in return, which represents the candidate.

The new candidate is then passed into RTCPeerConnection.addIceCandidate() to add the candidate to the list of candidates for WebRTC to consider using for the connection being established.

This example could be simplified somewhat; you may more often see the code look something like this, taking advantage of more advanced ECMAScript 2016 features:

let handleNewIceCandidate = candidateSDP =>
  myPeerConnection.addIceCandidate(new RTCIceCandidate(candidateSDP));

Specifications

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

Browser compatibility

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidEdge MobileFirefox for AndroidOpera for AndroidiOS SafariSamsung Internet
Basic supportChrome Full support YesEdge Full support 15Firefox Full support 22IE ? Opera Full support YesSafari ? WebView Android Full support YesChrome Android Full support YesEdge Mobile Full support YesFirefox Android ? Opera Android Full support YesSafari iOS ? Samsung Internet Android Full support Yes

Legend

Full support  
Full support
Compatibility unknown  
Compatibility unknown

Document Tags and Contributors

Contributors to this page: Sheppy
Last updated by: Sheppy,