:default CSS pseudo-class

- WD

Chrome

  1. 139
  2. 140
  3. 141
  4. 142
  5. 143
  6. 144
  7. 145

Edge

  1. 139
  2. 140
  3. 141
  4. 142

Safari

  1. 18.4
  2. 18.5-18.6
  3. 26.0
  4. 26.1
  5. 26.2
  6. TP

Firefox

  1. 141
  2. 142
  3. 143
  4. 144
  5. 145
  6. 146
  7. 147

Opera

  1. 119
  2. 120
  3. 121
  4. 122

IE

  1. 8
  2. 9
  3. 10
  4. 11

Chrome for Android

  1. 142

Safari on iOS

  1. 18.3
  2. 18.4
  3. 18.5-18.6
  4. 26.0
  5. 26.1

Samsung Internet

  1. 26
  2. 27
  3. 28
  4. 29

Opera Mini

  1. all

Opera Mobile

  1. 11.5
  2. 12
  3. 12.1
  4. 80

UC Browser for Android

  1. 15.5

Android Browser

  1. 4.2-4.3
  2. 4.4
  3. 4.4.3-4.4.4
  4. 142

Firefox for Android

  1. 144

QQ Browser

  1. 14.9

Baidu Browser

  1. 13.52

KaiOS Browser

  1. 2.5
  2. 3.0-3.1

Whether <option selected> matches :default (per the spec) was not tested since <select>s and <option>s are generally not styleable, which makes it hard to formulate a test for this.