CSS outline properties

- CR

The CSS outline properties draw a border around an element that does not affect layout, making it ideal for highlighting. This covers the outline shorthand, as well as outline-width, outline-style, outline-color and outline-offset.

IE

  1. 5.5 - 7
  2. 8
  3. 9 - 10
  4. 11

Edge

  1. 12 - 14
  2. 15 - 81
  3. 83

Firefox

  1. 2 - 77
  2. 78
  3. 79 - 80

Chrome

  1. 4 - 81
  2. 83
  3. 84 - 86

Safari

  1. 3.1 - 13
  2. 13.1
  3. 14 - TP

Opera

  1. 9 - 11.5
  2. 11.6 - 12
  3. 12.1
  4. 15 - 68
  5. 69

iOS Safari

  1. 3.2 - 13.3
  2. 13.4
  3. 14.0

Opera Mini

  1. all

Android Browser

  1. 2.1 - 4.4.4
  2. 81

Blackberry Browser

  1. 7
  2. 10

Opera Mobile

  1. 10 - 11.5
  2. 12 - 12.1
  3. 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 - 11.2
  2. 12.0

QQ Browser

  1. 10.4

Baidu Browser

  1. 7.12

KaiOS Browser

  1. 2.5

Firefox also supports the non-standard -moz-outline-radius property that acts similar to border-radius.

Resources:
MDN Web Docs - CSS outline
CSS Basic User Interface Module Level 3