Can I use
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CSS3 Text-shadow

- CR

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

Chrome

  1. ✅ 4 - 134: Supported
  2. ✅ 135: Supported
  3. ✅ 136 - 138: Supported

Edge

  1. ✅ 12 - 18: Supported
  2. ✅ 79 - 134: Supported
  3. ✅ 135: Supported

Safari

  1. ◐ 3.1 - 3.2: Partial support
  2. ✅ 4 - 18.3: Supported
  3. ✅ 18.4: Supported
  4. ✅ 18.5 - TP: Supported

Firefox

  1. ❌ 2 - 3: Not supported
  2. ✅ 3.5 - 136: Supported
  3. ✅ 137: Supported
  4. ✅ 138 - 140: Supported

Opera

  1. ❌ 9: Not supported
  2. ✅ 9.5 - 116: Supported
  3. ✅ 117: Supported

IE

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

Chrome for Android

  1. ✅ 135: Supported

Safari on iOS

  1. ✅ 3.2 - 18.3: Supported
  2. ✅ 18.4: Supported
  3. ✅ 18.5: Supported

Samsung Internet

  1. ✅ 4 - 26: Supported
  2. ✅ 27: 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. ✅ 135: Supported

Firefox for Android

  1. ✅ 137: 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