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 - 127: Supported
  3. ✅ 128: Supported
  4. ✅ 129 - 131: Supported

Edge

  1. ❌ 12 - 18: Not supported
  2. ✅ 79 - 127: Supported
  3. ✅ 128: Supported

Safari

  1. ❌ 3.1 - 4: Not supported
  2. ✅ 5 - 17.5: Supported
  3. ✅ 17.6: Supported
  4. ✅ 18.0 - TP: Supported

Firefox

  1. ❌ 2 - 5: Not supported
  2. ✅ 6 - 129: Supported
  3. ✅ 130: Supported
  4. ✅ 131 - 133: Supported

Opera

  1. ◐ 9 - 10.6: Partial support
  2. ✅ 11 - 110: Supported
  3. ✅ 111: Supported

IE

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

Chrome for Android

  1. ✅ 128: Supported

Safari on iOS

  1. ❌ 3.2: Not supported
  2. ✅ 4 - 17.5: Supported
  3. ✅ 17.6: Supported
  4. ✅ 18.0: Supported

Samsung Internet

  1. ✅ 4 - 24: Supported
  2. ✅ 25: Supported

Opera Mini

  1. ❌ all: Not supported

Opera Mobile

  1. ◐ 10 - 11: Partial support
  2. ✅ 11.1 - 12.1: Supported
  3. ✅ 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. ✅ 128: Supported

Firefox for Android

  1. ✅ 127: Supported

QQ Browser

  1. ✅ 14.9: Supported

Baidu Browser

  1. ✅ 13.52: Supported

KaiOS Browser

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