Can I use
?

Server-sent events

- LS

Method of continuously sending data from a server to the browser, rather than repeatedly requesting it (EventSource interface, used to fall under HTML5)

Chrome

  1. 4 - 5: Not supported
  2. 6 - 113: Supported
  3. 114: Supported
  4. 115 - 117: Supported

Edge

  1. 12 - 18: Not supported
  2. 79 - 113: Supported
  3. 114: Supported

Safari

  1. 3.1 - 4: Not supported
  2. 5 - 16.4: Supported
  3. 16.5: Supported
  4. 16.6 - TP: Supported

Firefox

  1. 2 - 5: Not supported
  2. 6 - 112: Supported
  3. 113: Supported
  4. 114 - 115: Supported

Opera

  1. 9 - 10.6: Partial support
  2. 11 - 98: Supported
  3. 99: Supported

IE

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

Chrome for Android

  1. 114: Supported

Safari on iOS

  1. 3.2: Not supported
  2. 4 - 16.4: Supported
  3. 16.5: Supported
  4. 17: Supported

Samsung Internet

  1. 4 - 20: Supported
  2. 21: Supported

Opera Mini

  1. all: Not supported

Opera Mobile

  1. 10 - 11: Partial support
  2. 11.1 - 12.1: Supported
  3. 73: Supported

UC Browser for Android

  1. 13.4: Supported

Android Browser

  1. 2.1 - 4.3: Not supported
  2. 4.4 - 4.4.4: Supported
  3. 113: Supported

Firefox for Android

  1. 113: Supported

QQ Browser

  1. 13.1: Supported

Baidu Browser

  1. 13.18: Supported

KaiOS Browser

  1. 2.5: Supported
  2. 3: Supported
Resources:
Polyfill
has.js test
HTML5 Rocks tutorial