(Translated by https://www.hiragana.jp/)
ui-serif, ui-sans-serif, ui-monospace and ui-rounded values for font-family | Can I use... Support tables for HTML5, CSS3, etc

ui-serif, ui-sans-serif, ui-monospace and ui-rounded values for font-family

- WD

Allows more control when choosing system interface fonts

Chrome

  1. 4 - 124: Not supported
  2. 125: Not supported
  3. 126 - 128: Not supported

Edge

  1. 12 - 124: Not supported
  2. 125: Not supported

Safari

  1. 3.1 - 13: Not supported
  2. 13.1 - 17.4: Supported
  3. 17.5: Supported
  4. 17.6 - TP: Supported

Firefox

  1. 2 - 125: Not supported
  2. 126: Not supported
  3. 127 - 129: Not supported

Opera

  1. 9 - 109: Not supported
  2. 110: Not supported

IE

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

Chrome for Android

  1. 125: Not supported

Safari on iOS

  1. 3.2 - 13.3: Not supported
  2. 13.4 - 17.4: Supported
  3. 17.5: Supported
  4. 17.6: Supported

Samsung Internet

  1. 4 - 24: Not supported
  2. 25: Not supported

Opera Mini

  1. all: Not supported

Opera Mobile

  1. 10 - 12.1: Not supported
  2. 80: Not supported

UC Browser for Android

  1. 15.5: Not supported

Android Browser

  1. 2.1 - 4.4.4: Not supported
  2. 125: Not supported

Firefox for Android

  1. 126: Not supported

QQ Browser

  1. 14.9: Not supported

Baidu Browser

  1. 13.52: Not supported

KaiOS Browser

  1. 2.5: Not supported
  2. 3: Not supported
Resources:
Chromium support bug
ui-serif Firefox support bug
ui-sans-serif Firefox support bug
ui-monospace Firefox support bug
ui-rounded Firefox support bug
WebKit Safari 13.1 announcement