Can I use
?

Shadow DOM (deprecated V0 spec)

- UNOFF

Original V0 version of the Shadow DOM specification. See Shadow DOM V1 for support for the latest version.

Chrome

  1. 4 - 24: Not supported
  2. 25 - 34: Supported
  3. 35 - 79: Supported
  4. 80 - 112: Not supported
  5. 113: Not supported
  6. 114 - 116: Not supported

Edge

  1. 12 - 18: Not supported
  2. 79: Supported
  3. 80 - 112: Not supported
  4. 113: Not supported

Safari

  1. 3.1 - 16.4: Not supported
  2. 16.5: Not supported
  3. 16.6 - TP: Not supported

Firefox

  1. 2 - 28: Not supported
  2. 29 - 60: Disabled by default
  3. 61 - 112: Not supported
  4. 113: Not supported
  5. 114 - 115: Not supported

Opera

  1. 9 - 12.1: Not supported
  2. 15 - 21: Supported
  3. 22 - 66: Supported
  4. 67 - 98: Not supported
  5. 99: Not supported

IE

  1. 5.5 - 10: Not supported
  2. 11: Not supported

Chrome for Android

  1. 113: Not supported

Safari on iOS

  1. 3.2 - 16.4: Not supported
  2. 16.5: Not supported

Samsung Internet

  1. 4: Supported
  2. 5 - 12.0: Supported
  3. 13.0 - 20: Not supported
  4. 21: Not supported

Opera Mini

  1. all: Not supported

Opera Mobile

  1. 10 - 12.1: Not supported
  2. 73: Not supported

UC Browser for Android

  1. 13.4: Supported

Android Browser

  1. 2.1 - 4.3: Not supported
  2. 4.4 - 4.4.4: Supported
  3. 113: Not supported

Firefox for Android

  1. 113: Not supported

QQ Browser

  1. 13.1: Supported

Baidu Browser

  1. 13.18: Not supported

KaiOS Browser

  1. 2.5: Supported
  2. 3: Not supported
Resources:
Safari implementation bug
Firefox implementation bug
Google Developers - Shadow DOM v1: self-contained web components
HTML5Rocks - Shadow DOM 101 article