High Definition (HD) phone sound quality

OpusTel uses the Opus Codec from App to App. This means more Hertz and much better quality. The new, improved quality over the old GSM voice quality means more pleasant phone conversations.

To get the best voice and music quality, the Internet connection must be good. UMTS or 4G or LTE or Wifi is required.

The iPhone 4S, the iPhone 5, the iPhone 6 and the Samsung Galaxy S5 LTE provides the best quality. 

The OpusTel App with the landline phone number works as well with data only mobile contracts.