Can I use
?

WebM video format

- OTHER

Multimedia format designed to provide a royalty-free, high-quality open video compression format for use with HTML5 video. WebM supports the video codec VP8 and VP9.

IE

  1. 5.5 - 8: Not supported
  2. 9 - 10: Not supported (but has polyfill available)
  3. 11: Not supported (but has polyfill available)

Edge

  1. 12 - 13: Not supported (but has polyfill available)
  2. 14 - 18: Partial support
  3. 79 - 86: Supported
  4. 87: Supported

Firefox

  1. 2 - 3.6: Not supported
  2. 4 - 27: Partial support
  3. 28 - 83: Supported
  4. 84: Supported
  5. 85 - 86: Supported

Chrome

  1. 4 - 5: Not supported
  2. 6 - 24: Partial support
  3. 25 - 86: Supported
  4. 87: Supported
  5. 88 - 90: Supported

Safari

  1. 3.1: Not supported
  2. 3.2 - 5.1: Not supported (but has polyfill available)
  3. 6 - 12: Not supported (but has polyfill available)
  4. 12.1 - 13.1: Partial support
  5. 14: Partial support
  6. TP: Partial support

Opera

  1. 9 - 10.5: Not supported
  2. 10.6 - 15: Partial support
  3. 16 - 71: Supported
  4. 72: Supported

iOS Safari

  1. 3.2 - 12.1: Not supported
  2. 12.2 - 13.7: Partial support
  3. 14: Partial support

Opera Mini

  1. all: Not supported

Android Browser

  1. 2.1 - 2.2: Not supported
  2. 2.3 - 4.4.4: Partial support
  3. 81: Supported

Opera Mobile

  1. 10 - 12.1: Not supported
  2. 59: Partial support

Chrome for Android

  1. 87: Supported

Firefox for Android

  1. 83: Supported

UC Browser for Android

  1. 12.12: Supported

Samsung Internet

  1. 4: Partial support
  2. 5 - 12.0: Supported
  3. 13.0: Supported

QQ Browser

  1. 10.4: Supported

Baidu Browser

  1. 7.12: Supported

KaiOS Browser

  1. 2.5: Supported
Resources:
Wikipedia article
Official website