This feature has been removed from the Web standards. Though some browsers may still support it, it is in the process of being dropped. Avoid using it and update existing code if possible; see the compatibility table at the bottom of this page to guide your decision. Be aware that this feature may cease to work at any time.


The MediaRecorder.onwarning event handler (part of the MediaRecorder API) handles the recordingwarning event, allowing you to run code in response to non-fatal errors being thrown during media recording via a MediaRecorder, which don't halt recording.


MediaRecorder.onwarning = function(event) { ... }
MediaRecorder.addEventListener('warning', function(event) { ... })



  mediaRecorder.onwarning = function(e) {
    console.log("A warning has been raised: " + e.message);



Contains information about the error that occurred.


Specification Status Comment
MediaStream Recording Working Draft Initial definition

Browser compatibility

FeatureChromeEdgeFirefoxInternet ExplorerOperaSafari
Basic support471 ?25 ? ? ?
FeatureAndroid webviewChrome for AndroidEdge mobileFirefox for AndroidOpera AndroidiOS SafariSamsung Internet
Basic support ? ? ?25 ? ? ?

1. From version 47: this feature is behind the Experimental Web Platform features preference (needs to be set to Enabled). To change preferences in Chrome, visit chrome://flags.

See also

Document Tags and Contributors

Last updated by: lucian95,