Royalty-free open audio codec by IETF, which incorporated SILK from Skype and CELT from Xiph.org, to serve higher sound quality and lower latency at the same bitrate.

IE

  1. 5.5 - 10
  2. 11

Edge

  1. 12 - 13
  2. 14 - 81
  3. 83

Firefox

  1. 2 - 14
  2. 15 - 77
  3. 78
  4. 79 - 80

Chrome

  1. 4 - 32
  2. 33 - 81
  3. 83
  4. 84 - 86

Safari

  1. 3.1 - 10.1
  2. 11 - 13
  3. 13.1
  4. 14 - TP

Opera

  1. 9 - 19
  2. 20 - 68
  3. 69

iOS Safari

  1. 3.2 - 10.3
  2. 11 - 13.3
  3. 13.4
  4. 14.0

Opera Mini

  1. all

Android Browser

  1. 2.1 - 4.4.4
  2. 81

Blackberry Browser

  1. 7
  2. 10

Opera Mobile

  1. 10 - 12.1
  2. 46

Chrome for Android

  1. 81

Firefox for Android

  1. 68

IE Mobile

  1. 10
  2. 11

UC Browser for Android

  1. 12.12

Samsung Internet

  1. 4
  2. 5 - 11.2
  3. 12.0

QQ Browser

  1. 10.4

Baidu Browser

  1. 7.12

KaiOS Browser

  1. 2.5

Support refers to this format's use in the audio element, not other conditions.

For Opera the Linux version may be able to play it when the GStreamer module is up to date and the served mime-type is 'audio/ogg'.

Resources:
Google's statement about the use of VP8 and Opus codec for WebRTC standard
Introduction of Opus by Mozilla
Microsoft Edge feature request on UserVoice