We're looking for a person or people to help audit MDN to find places we could speed up. Is this you or someone you know? Check out the RFP: https://mzl.la/2IHcMiE


The insertDTMF() method on the RTCDTMFSender interface starts sending DTMF tones to the remote peer over the RTCPeerConnection. Sending of the tones is performed asynchronously, with tonechange events sent to the RTCDTMFSender every time a tone starts or ends.

As long as the connection is active, you can send tones at any time. Calling insertDTMF() will append the specified tones to the end of the current tone buffer, so that those tones play after the previously-enqueued tones.


RTCDTMFSender.insertDTMF(tones[, duration[, interToneGap]]);


A DOMString containing the DTMF codes to be transmitted to the recipient. Specifying an empty string as the tones parameter clears the tone buffer, aborting any currently queued tones. A "," character inserts a two second delay.
duration Optional
The amount of time, in milliseconds, that each DTMF tone should last. This value must be between 40 ms and 6000 ms (6 seconds), inclusive. The default is 100 ms.
interToneGap Optional
The length of time, in milliseconds, to wait between tones. The browser will enforce a minimum value of 30 ms (that is, if you specify a lower value, 30 ms will be used instead); the default is 70 ms.

Return value



The DTMF tones couldn't be sent because the track has been stopped, or is in a read-only or inactive state.
One or more of the characters in tones is not valid DTMF.




Specification Status Comment
WebRTC 1.0: Real-time Communication Between Browsers
The definition of 'RTCDTMFSender.insertDTMF()' in that specification.
Candidate Recommendation  

Browser compatibility

FeatureChromeEdgeFirefoxInternet ExplorerOperaSafari
Basic support Yes ?52 No ? ?
FeatureAndroid webviewChrome for AndroidEdge mobileFirefox for AndroidOpera AndroidiOS SafariSamsung Internet
Basic support No Yes ?52 ? ? ?

See also

Document Tags and Contributors

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