Can I use
?

asm.js

- OTHER

An extraordinarily optimizable, low-level subset of JavaScript, intended to be a compile target from languages like C++.

Chrome

  1. 4 - 27: Not supported
  2. 28 - 116: Partial support
  3. 117: Partial support
  4. 118 - 120: Partial support

Edge

  1. 12: Disabled by default
  2. 13 - 18: Supported
  3. 79 - 116: Partial support
  4. 117: Partial support

Safari

  1. 3.1 - 16.6: Not supported
  2. 17.0: Not supported
  3. 17.1 - TP: Not supported

Firefox

  1. 2 - 21: Not supported
  2. 22 - 116: Supported
  3. 117: Supported
  4. 118 - 120: Supported

Opera

  1. 9 - 12.1: Not supported
  2. 15 - 101: Partial support
  3. 102: Partial support

IE

  1. 5.5 - 10: Not supported
  2. 11: Not supported

Chrome for Android

  1. 117: Partial support

Safari on iOS

  1. 3.2 - 16.6: Not supported
  2. 17.0: Not supported
  3. 17.1: Not supported

Samsung Internet

  1. 4: Not supported
  2. 5 - 21: Partial support
  3. 22: Partial support

Opera Mini

  1. all: Not supported

Opera Mobile

  1. 10 - 12.1: Not supported
  2. 73: Partial support

UC Browser for Android

  1. 15.5: Partial support

Android Browser

  1. 2.1 - 4.4.4: Not supported
  2. 117: Partial support

Firefox for Android

  1. 117: Supported

QQ Browser

  1. 13.1: Partial support

Baidu Browser

  1. 13.18: Partial support

KaiOS Browser

  1. 2.5: Supported
  2. 3: Supported

asm.js is mostly rendered obsolete with the introduction of WebAssembly and is therefore no longer recommended

Resources:
Homepage
Bringing Asm.js to Chakra and Microsoft Edge
Microsoft Edge support announcement
MDN article about asm.js
Wikipedia article about asm.js
Source for spec and tools