CSS3 Box-shadow

- CR

Method of displaying an inner or outer shadow effect to elements

Chrome

  1. 4 - 9: Supported
  2. 10 - 108: Supported
  3. 109: Supported
  4. 110 - 112: Supported

Edge

  1. 12 - 108: Supported
  2. 109: Supported

Safari

  1. 3.1 - 4: Partial support
  2. 5: Supported
  3. 5.1 - 16.2: Supported
  4. 16.3: Supported
  5. TP: Supported

Firefox

  1. 2 - 3: Not supported
  2. 3.5 - 3.6: Supported
  3. 4 - 108: Supported
  4. 109: Supported
  5. 110 - 111: Supported

Opera

  1. 9 - 10.1: Not supported
  2. 10.5 - 93: Supported
  3. 94: Supported

IE

  1. 5.5 - 8: Not supported
  2. 9 - 10: Supported
  3. 11: Supported

Chrome for Android

  1. 109: Supported

Safari on iOS

  1. 3.2: Partial support
  2. 4 - 4.3: Supported
  3. 5 - 16.2: Supported
  4. 16.3: Supported

Samsung Internet

  1. 4 - 18.0: Supported
  2. 19.0: Supported

Opera Mini

  1. all: Not supported

Opera Mobile

  1. 10: Not supported
  2. 11 - 12.1: Supported
  3. 73: Supported

UC Browser for Android

  1. 13.4: Supported

Android Browser

  1. 2.1 - 3: Partial support
  2. 4 - 4.4.4: Supported
  3. 109: Supported

Firefox for Android

  1. 109: Supported

QQ Browser

  1. 13.1: Supported

Baidu Browser

  1. 13.18: Supported

KaiOS Browser

  1. 2.5: Supported

Can be partially emulated in older IE versions using the non-standard "shadow" filter.

Resources:
Demo of various effects
MDN Web Docs - box-shadow
WebPlatform Docs
Live editor