Can I use
?

MathML

- REC

Special tags that allow mathematical formulas and notations to be written on web pages.

Chrome

  1. 4 - 23: Not supported (but has polyfill available)
  2. 24: Supported
  3. 25 - 96: Not supported (but has polyfill available)
  4. 97 - 108: Disabled by default
  5. 109 - 110: Supported
  6. 111: Supported
  7. 112 - 114: Supported

Edge

  1. 12 - 18: Not supported
  2. 79 - 96: Not supported (but has polyfill available)
  3. 97 - 108: Disabled by default
  4. 109 - 110: Supported
  5. 111: Supported

Safari

  1. 3.1 - 9.1: Partial support
  2. 10 - 16.3: Supported
  3. 16.4: Supported
  4. 16.5 - TP: Supported

Firefox

  1. 2 - 3.6: Supported
  2. 4 - 110: Supported
  3. 111: Supported
  4. 112 - 113: Supported

Opera

  1. 9: Not supported
  2. 9.5 - 12.1: Partial support
  3. 15 - 82: Not supported (but has polyfill available)
  4. 83 - 94: Disabled by default
  5. 95: Supported

IE

  1. 5.5: Not supported
  2. 6 - 8: Not supported (but has polyfill available)
  3. 9 - 10: Not supported
  4. 11: Not supported

Chrome for Android

  1. 111: Supported

Safari on iOS

  1. 3.2 - 4.3: Not supported (but has polyfill available)
  2. 5 - 16.3: Supported
  3. 16.4: Supported
  4. 16.5: Supported

Samsung Internet

  1. 4 - 19.0: Not supported (but has polyfill available)
  2. 20: Not supported (but has polyfill available)

Opera Mini

  1. all: Not supported (but has polyfill available)

Opera Mobile

  1. 10 - 12.1: Not supported (but has polyfill available)
  2. 73: Not supported (but has polyfill available)

UC Browser for Android

  1. 13.4: Not supported (but has polyfill available)

Android Browser

  1. 2.1 - 4.4.4: Not supported (but has polyfill available)
  2. 111: Supported

Firefox for Android

  1. 110: Supported

QQ Browser

  1. 13.1: Not supported (but has polyfill available)

Baidu Browser

  1. 13.18: Not supported (but has polyfill available)

KaiOS Browser

  1. 2.5: Supported
  2. 3: Supported

Support was added in Chrome 24, but temporarily removed afterwards due to instability.

Resources:
MDN Web Docs - MathML
Wikipedia
MathML torture test
MathML in Chromium Project Roadmap
Cross-browser support script