What are the minimum browser requirements for Twilio Client?
Twilio Client for Browser (Flash)
The flash base supports Google Chrome 11+ (however, Flash is currently not compatible with Chrome incognito mode), Internet Explorer 7+, Safari 5+, and Firefox 3.6+ with Flash 10.1 or higher installed.
Twilio Client for Browser (WebRTC)
You must be using version 1.1 or later of Twilio Client with a browser which supports WebRTC.
Also see detailed network requirements for Twilio Client.