CSS font-feature-settings

- REC

Method of applying advanced typographic and language-specific font features to supported OpenType fonts.

Chrome

  1. 4 - 15: Not supported
  2. 16 - 20: Partial support
  3. 21 - 47: Supported
  4. 48 - 130: Supported
  5. 131: Supported
  6. 132 - 134: Supported

Edge

  1. 12 - 130: Supported
  2. 131: Supported

Safari

  1. 3.1 - 3.2: Not supported
  2. 4 - 6: Partial support
  3. 6.1 - 9: Not supported
  4. 9.1 - 18.0: Supported
  5. 18.1: Supported
  6. 18.2 - TP: Supported

Firefox

  1. 2 - 3.6: Not supported
  2. 4 - 14: Partial support
  3. 15 - 33: Supported
  4. 34 - 131: Supported
  5. 132: Supported
  6. 133 - 135: Supported

Opera

  1. 9 - 12.1: Not supported
  2. 15 - 34: Supported
  3. 35 - 113: Supported
  4. 114: Supported

IE

  1. 5.5 - 9: Not supported
  2. 10: Supported
  3. 11: Supported

Chrome for Android

  1. 131: Supported

Safari on iOS

  1. 3.2 - 6.1: Partial support
  2. 7 - 9.2: Not supported
  3. 9.3 - 18.0: Supported
  4. 18.1: Supported
  5. 18.2: Supported

Samsung Internet

  1. 4: Supported
  2. 5 - 25: Supported
  3. 26: Supported

Opera Mini

  1. all: Not supported

Opera Mobile

  1. 10 - 12.1: Not supported
  2. 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. 131: Supported

Firefox for Android

  1. 132: Supported

QQ Browser

  1. 14.9: Supported

Baidu Browser

  1. 13.52: Supported

KaiOS Browser

  1. 2.5: Supported
  2. 3: Supported

Whenever possible, font-variant shorthand property or an associated longhand property, font-variant-ligatures, font-variant-caps, font-variant-east-asian, font-variant-alternates, font-variant-numeric or font-variant-position should be used. This property is a low-level feature designed to handle special cases where no other way to enable or access an OpenType font feature exists. In particular, this CSS property shouldn't be used to enable small caps.

Resources:
MDN Web Docs - font-feature-settings
Mozilla hacks article
Syntax for OpenType features in CSS (Adobe Typekit Help)
Detailed tables on accessibility support
Demo pages (IE/Firefox only)
WebPlatform Docs
OpenType layout feature tag registry