Service Workers

- CR

Method that enables applications to take advantage of persistent background processing, including hooks to enable bootstrapping of web applications while offline.

IE

  1. 5.5 - 10
  2. 11

Edge

  1. 12 - 14
  2. 15 - 16
  3. 17 - 81
  4. 83

Firefox

  1. 2 - 32
  2. 33 - 43
  3. 44
  4. 45
  5. 46 - 51
  6. 52
  7. 53 - 59
  8. 60
  9. 61 - 67
  10. 68
  11. 69 - 75
  12. 76
  13. 77 - 78

Chrome

  1. 4 - 39
  2. 40 - 44
  3. 45 - 81
  4. 83
  5. 84 - 86

Safari

  1. 3.1 - 11
  2. 11.1 - 13
  3. 13.1
  4. TP

Opera

  1. 9 - 26
  2. 27 - 31
  3. 32 - 67
  4. 68

iOS Safari

  1. 3.2 - 11.2
  2. 11.3 - 13.3
  3. 13.4

Opera Mini

  1. all

Android Browser

  1. 2.1 - 4.4.4
  2. 81

Blackberry Browser

  1. 7
  2. 10

Opera Mobile

  1. 10 - 12.1
  2. 46

Chrome for Android

  1. 81

Firefox for Android

  1. 68

IE Mobile

  1. 10
  2. 11

UC Browser for Android

  1. 12.12

Samsung Internet

  1. 4 - 10.1
  2. 11.1

QQ Browser

  1. 10.4

Baidu Browser

  1. 7.12

KaiOS Browser

  1. 2.5

Details on partial support can be found on is ServiceWorker Ready?

Resources:
MDN Web Docs - Service Workers
List of various resources
HTML5Rocks article (introduction)