async attribute for external scripts

- LS

The boolean async attribute on script elements allows the external JavaScript file to run when it's available, without delaying page load first.

Chrome

  1. 4 - 7: Not supported
  2. 8 - 107: Supported
  3. 108: Supported
  4. 109 - 111: Supported

Edge

  1. 12 - 106: Supported
  2. 107: Supported

Safari

  1. 3.1 - 4: Not supported
  2. 5: Partial support
  3. 5.1 - 16.0: Supported
  4. 16.1: Supported
  5. 16.2 - TP: Supported

Firefox

  1. 2 - 3.5: Not supported
  2. 3.6 - 106: Supported
  3. 107: Supported
  4. 108 - 109: Supported

Opera

  1. 9 - 12.1: Not supported
  2. 15 - 91: Supported
  3. 92: Supported

IE

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

Chrome for Android

  1. 107: Supported

Safari on iOS

  1. 3.2 - 4.3: Not supported
  2. 5 - 16.0: Supported
  3. 16.1: Supported

Samsung Internet

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

Opera Mini

  1. all: Not supported

Opera Mobile

  1. 10 - 12.1: Not supported
  2. 72: Supported

UC Browser for Android

  1. 13.4: Supported

Android Browser

  1. 2.1 - 2.3: Not supported
  2. 3 - 4.4.4: Supported
  3. 107: Supported

Firefox for Android

  1. 106: Supported

QQ Browser

  1. 13.1: Supported

Baidu Browser

  1. 13.18: Supported

KaiOS Browser

  1. 2.5: Supported
Resources:
MDN Web Docs - Script attributes
has.js test
Demo
async vs defer attributes