Can I use
?

FileReaderSync

- WD

Allows files to be read synchronously in Web Workers

Chrome

  1. ﹖ 4 - 14: Support unknown
  2. ✅ 15 - 156: Supported
  3. ✅ 157: Supported
  4. ✅ 158 - 160: Supported

Edge

  1. ✅ 12 - 155: Supported
  2. ✅ 156: Supported

Safari

  1. ❌ 3.1 - 5.1: Not supported
  2. ✅ 6 - 27.1: Supported
  3. ✅ 27.2: Supported
  4. ✅ 27.3 - TP: Supported

Firefox

  1. ❌ 2 - 7: Not supported
  2. ✅ 8 - 159: Supported
  3. ✅ 160: Supported
  4. ✅ 161 - 163: Supported

Opera

  1. ❌ 9 - 10.1: Not supported
  2. ﹖ 10.5 - 11.5: Support unknown
  3. ✅ 11.6 - 138: Supported
  4. ✅ 139: Supported

IE

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

Chrome for Android

  1. ✅ 157: Supported

Safari on iOS

  1. ❌ 3.2 - 5.1: Not supported
  2. ✅ 6 - 26.6: Supported
  3. ✅ 27.0: Supported
  4. ✅ 27.1 - 27.2: Supported

Samsung Internet

  1. ✅ 4 - 30: Supported
  2. ✅ 31: Supported

Opera Mini

  1. ❌ all: Not supported

Opera Mobile

  1. ❌ 10: Not supported
  2. ﹖ 11 - 11.1: Support unknown
  3. ✅ 11.5 - 12.1: Supported
  4. ✅ 80: Supported

UC Browser for Android

  1. ✅ 15.5: Supported

Android Browser

  1. ❌ 2.1 - 4.3: Not supported
  2. ✅ 4.4 - 4.4.4: Supported
  3. ✅ 157: Supported

Firefox for Android

  1. ✅ 160: Supported

QQ Browser

  1. ✅ 14.9: Supported

Baidu Browser

  1. ✅ 13.52: Supported

KaiOS Browser

  1. ✅ 2.5: Supported
  2. ✅ 3: Supported
Resources:
MDN Web Docs - FileReaderSync