:default CSS pseudo-class
- WDThe :default pseudo-class matches checkboxes and radio buttons which are checked by default, <option>s with the selected attribute, and the default submit button (if any) of a form.
Chrome
- ﹖ 4 - 14: Support unknown
- ◐ 15 - 50: Partial support
- ✅ 51 - 154: Supported
- ✅ 155: Supported
- ✅ 156 - 158: Supported
Edge
- ❌ 12 - 18: Not supported
- ✅ 79 - 154: Supported
- ✅ 155: Supported
Safari
- ﹖ 3.1 - 5: Support unknown
- ◐ 5.1 - 10: Partial support
- ✅ 10.1 - 26.6: Supported
- ✅ 27: Supported
- ✅ 27.1 - TP: Supported
Firefox
- ﹖ 2 - 3.6: Support unknown
- ✅ 4 - 157: Supported
- ✅ 158: Supported
- ✅ 159 - 161: Supported
Opera
- ﹖ 9 - 11.5: Support unknown
- ◐ 11.6 - 12.1: Partial support
- ◐ 15 - 37: Partial support
- ✅ 38 - 134: Supported
- ✅ 135: Supported
IE
- ❌ 5.5 - 10: Not supported
- ❌ 11: Not supported
Chrome for Android
- ✅ 155: Supported
Safari on iOS
- ﹖ 3.2 - 6.1: Support unknown
- ◐ 7 - 10.2: Partial support
- ✅ 10.3 - 26.6: Supported
- ✅ 27.0: Supported
- ✅ 27.1 - 27.2: Supported
Samsung Internet
- ◐ 4: Partial support
- ✅ 5 - 29: Supported
- ✅ 30: Supported
Opera Mini
- ◐ all: Partial support
Opera Mobile
- ﹖ 10 - 12: Support unknown
- ◐ 12.1: Partial support
- ✅ 80: Supported
UC Browser for Android
- ✅ 15.5: Supported
Android Browser
- ﹖ 2.1 - 3: Support unknown
- ◐ 4 - 4.4.4: Partial support
- ✅ 155: Supported
Firefox for Android
- ✅ 158: Supported
QQ Browser
- ✅ 14.9: Supported
Baidu Browser
- ✅ 13.52: Supported
KaiOS Browser
- ✅ 2.5: Supported
- ✅ 3: Supported
Whether <option selected> matches :default (per the spec) was not tested since <select>s and <option>s are generally not styleable, which makes it hard to formulate a test for this.