CSS zoom

- UNOFF

Non-standard method of scaling content.

IE

  1. 5.5 - 7: Supported
  2. 8 - 10: Supported
  3. 11: Supported

Edge

  1. 12 - 79: Supported
  2. 80: Supported

Firefox

  1. 2 - 71: Not supported
  2. 72: Not supported
  3. 73 - 74: Not supported

Chrome

  1. 4 - 79: Supported
  2. 80: Supported
  3. 81 - 83: Supported

Safari

  1. 3.1 - 3.2: Not supported
  2. 4 - 12.1: Supported
  3. 13: Supported
  4. TP: Supported

Opera

  1. 9 - 12.1: Not supported
  2. 15 - 65: Supported
  3. 66: Supported

iOS Safari

  1. 3.2: Not supported
  2. 4 - 13.1: Supported
  3. 13.2: Supported
  4. 13.3: Supported

Opera Mini

  1. all: Not supported

Android Browser

  1. 2.1 - 4.4.4: Supported
  2. 76: Supported

Blackberry Browser

  1. 7: Supported
  2. 10: Supported

Opera Mobile

  1. 10 - 12.1: Not supported
  2. 46: Supported

Chrome for Android

  1. 79: Supported

Firefox for Android

  1. 68: Not supported

IE Mobile

  1. 10: Supported
  2. 11: Supported

UC Browser for Android

  1. 12.12: Supported

Samsung Internet

  1. 4 - 9.2: Supported
  2. 10.1: Supported

QQ Browser

  1. 1.2: Supported

Baidu Browser

  1. 7.12: Supported

KaiOS Browser

  1. 2.5: Not supported

Originally implemented only in Internet Explorer. Although several other browsers support the property, using transform: scale() is the recommended solution to scale content.

Resources:
Article explaining usage of zoom as the hack for fixing rendering bugs in IE6 and IE7.
CSS Tricks
Safari Developer Library
MDN Web Docs - CSS zoom
WebPlatform Docs
MSDN Library