From iOS 14.3, WKWebView has full support for WebRTC. I was able to get the voice call to work. Unfortunately, I ran into a blocking issue when integrating CallKit. Basically CallKit breaks getUserMedia JavaScript call. I believe it's because CallKit gives the calling process exclusive access to the microphone, but WKWebView renderer runs in a separate process. Is there a solution to this problem? The reason I'm implementing the feature on top of webview instead of native WebRTC SDK is due to the size of the SDK. It adds 10M to the app size and our app is already too big.