CSS3 Text-shadow

- CR

Method of applying one or more shadow or blur effects to text

Chrome

  1. 4 - 124: Supported
  2. 125: Supported
  3. 126 - 128: Supported

Edge

  1. 12 - 18: Supported
  2. 79 - 123: Supported
  3. 124: Supported

Safari

  1. 3.1 - 3.2: Partial support
  2. 4 - 17.4: Supported
  3. 17.5: Supported
  4. 17.6 - TP: Supported

Firefox

  1. 2 - 3: Not supported
  2. 3.5 - 125: Supported
  3. 126: Supported
  4. 127 - 129: Supported

Opera

  1. 9: Not supported
  2. 9.5 - 108: Supported
  3. 109: Supported

IE

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

Chrome for Android

  1. 124: Supported

Safari on iOS

  1. 3.2 - 17.4: Supported
  2. 17.5: Supported
  3. 17.6: Supported

Samsung Internet

  1. 4 - 23: Supported
  2. 24: Supported

Opera Mini

  1. all: Partial support

Opera Mobile

  1. 10 - 12.1: Supported
  2. 80: Supported

UC Browser for Android

  1. 15.5: Supported

Android Browser

  1. 2.1 - 4.4.4: Supported
  2. 124: Supported

Firefox for Android

  1. 125: Supported

QQ Browser

  1. 14.9: Supported

Baidu Browser

  1. 13.52: Supported

KaiOS Browser

  1. 2.5: Supported
  2. 3: Supported

Opera Mini ignores the blur-radius set, so no blur effect is visible. Text-shadow behavior can be somewhat emulated in older IE versions using the non-standard "dropshadow" or "glow" filters.

Resources:
Mozilla hacks article
Live editor
WebPlatform Docs