Form validation

- LS

Method of setting required fields and field types without requiring JavaScript. This includes preventing forms from being submitted when appropriate, the checkValidity() method as well as support for the :invalid, :valid, and :required CSS pseudo-classes.

Chrome

  1. 4 - 9: Not supported
  2. 10 - 106: Supported
  3. 107: Supported
  4. 108 - 110: Supported

Edge

  1. 12 - 106: Supported
  2. 107: Supported

Safari

  1. 3.1 - 4: Not supported
  2. 5 - 10: Partial support
  3. 10.1 - 16.0: Supported
  4. 16.1: Supported
  5. 16.2 - TP: Supported

Firefox

  1. 2 - 3.6: Not supported
  2. 4 - 106: Supported
  3. 107: Supported
  4. 108 - 109: Supported

Opera

  1. 9 - 9.6: Not supported
  2. 10 - 91: Supported
  3. 92: Supported

IE

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

Chrome for Android

  1. 107: Supported

Safari on iOS

  1. 3.2: Not supported
  2. 4 - 10.2: Partial support
  3. 10.3 - 16.0: Supported
  4. 16.1: Supported

Samsung Internet

  1. 4 - 18.0: Supported
  2. 19.0: Supported

Opera Mini

  1. all: Partial support

Opera Mobile

  1. 10 - 12.1: Supported
  2. 72: Supported

UC Browser for Android

  1. 13.4: Supported

Android Browser

  1. 2.1 - 3: Not supported
  2. 4 - 4.4: Partial support
  3. 4.4.3: Supported
  4. 107: Supported

Firefox for Android

  1. 106: Supported

QQ Browser

  1. 13.1: Supported

Baidu Browser

  1. 13.18: Supported

KaiOS Browser

  1. 2.5: Partial support
Resources:
WebKit Blog: HTML Interactive Form Validation
WebPlatform Docs
Sub-features:
Pattern attribute for input fields
Minimum length attribute for input fields
maxlength attribute for input and textarea elements
:optional CSS pseudo-class