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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 - 143: Supported
  3. ✅ 144: Supported
  4. ✅ 145 - 147: Supported

Edge

  1. ✅ 12 - 143: Supported
  2. ✅ 144: Supported

Safari

  1. ❌ 3.1 - 4: Not supported
  2. ◐ 5 - 10: Partial support
  3. ✅ 10.1 - 26.1: Supported
  4. ✅ 26.2: Supported
  5. ✅ 26.3 - TP: Supported

Firefox

  1. ❌ 2 - 3.6: Not supported
  2. ✅ 4 - 146: Supported
  3. ✅ 147: Supported
  4. ✅ 148 - 150: Supported

Opera

  1. ❌ 9 - 9.6: Not supported
  2. ✅ 10 - 124: Supported
  3. ✅ 125: Supported

IE

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

Chrome for Android

  1. ✅ 144: Supported

Safari on iOS

  1. ❌ 3.2: Not supported
  2. ◐ 4 - 10.2: Partial support
  3. ✅ 10.3 - 26.1: Supported
  4. ✅ 26.2: Supported
  5. ✅ 26.3: Supported

Samsung Internet

  1. ✅ 4 - 28: Supported
  2. ✅ 29: Supported

Opera Mini

  1. ◐ all: Partial support

Opera Mobile

  1. ✅ 10 - 12.1: Supported
  2. ✅ 80: Supported

UC Browser for Android

  1. ✅ 15.5: Supported

Android Browser

  1. ❌ 2.1 - 3: Not supported
  2. ◐ 4 - 4.4: Partial support
  3. ✅ 4.4.3: Supported
  4. ✅ 144: Supported

Firefox for Android

  1. ◐ 147: Partial support

QQ Browser

  1. ✅ 14.9: Supported

Baidu Browser

  1. ✅ 13.52: Supported

KaiOS Browser

  1. ◐ 2.5: Partial support
  2. ✅ 3: Supported
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