:default CSS pseudo-class

The :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.

Spec	https://drafts.csswg.org/selectors-4/#the-default-pseudo
Status	Unofficial / Note

IE	Edge	Firefox	Chrome	Safari	Opera
			98
		95	97
		94	96	TP
11	95	93	95	15	80
10	94	92	94	14.1	79
9	93	91	93	14	78
8	92	90	92	13.1	77
Show all
7	91	89	91	13	76
6	90	88	90	12.1	75
5.5	89	87	89	12	74
	88	86	88	11.1	73
	87	85	87	11	72
	86	84	86	10.1	71
	85	83	85	10 ⁽¹⁾	70
	84	82	84	9.1 ⁽¹⁾	69
	83	81	83	9 ⁽¹⁾	68
	81	80	81	8 ⁽¹⁾	67
	80	79	80	7.1 ⁽¹⁾	66
	79	78	79	7 ⁽¹⁾	65
	18	77	78	6.1 ⁽¹⁾	64
	17	76	77	6 ⁽¹⁾	63
	16	75	76	5.1 ⁽¹⁾	62
	15	74	75	5	60
	14	73	74	4	58
	13	72	73	3.2	57
	12	71	72	3.1	56
		70	71		55
		69	70		54
		68	69		53
		67	68		52
		66	67		51
		65	66		50
		64	65		49
		63	64		48
		62	63		47
		61	62		46
		60	61		45
		59	60		44
		58	59		43
		57	58		42
		56	57		41
		55	56		40
		54	55		39
		53	54		38
		52	53		37 ⁽¹⁾
		51	52		36 ⁽¹⁾
		50	51		35 ⁽¹⁾
		49	50 ⁽¹⁾		34 ⁽¹⁾
		48	49 ⁽¹⁾		33 ⁽¹⁾
		47	48 ⁽¹⁾		32 ⁽¹⁾
		46	47 ⁽¹⁾		31 ⁽¹⁾
		45	46 ⁽¹⁾		30 ⁽¹⁾
		44	45 ⁽¹⁾		29 ⁽¹⁾
		43	44 ⁽¹⁾		28 ⁽¹⁾
		42	43 ⁽¹⁾		27 ⁽¹⁾
		41	42 ⁽¹⁾		26 ⁽¹⁾
		40	41 ⁽¹⁾		25 ⁽¹⁾
		39	40 ⁽¹⁾		24 ⁽¹⁾
		38	39 ⁽¹⁾		23 ⁽¹⁾
		37	38 ⁽¹⁾		22 ⁽¹⁾
		36	37 ⁽¹⁾		21 ⁽¹⁾
		35	36 ⁽¹⁾		20 ⁽¹⁾
		34	35 ⁽¹⁾		19 ⁽¹⁾
		33	34 ⁽¹⁾		18 ⁽¹⁾
		32	33 ⁽¹⁾		17 ⁽¹⁾
		31	32 ⁽¹⁾		16 ⁽¹⁾
		30	31 ⁽¹⁾		15 ⁽¹⁾
		29	30 ⁽¹⁾		12.1 ⁽²⁾
		28	29 ⁽¹⁾		12 ⁽²⁾
		27	28 ⁽¹⁾		11.6 ⁽²⁾
		26	27 ⁽¹⁾		11.5
		25	26 ⁽¹⁾		11.1
		24	25 ⁽¹⁾		11
		23	24 ⁽¹⁾		10.6
		22	23 ⁽¹⁾		10.5
		21	22 ⁽¹⁾		10.0-10.1
		20	21 ⁽¹⁾		9.5-9.6
		19	20 ⁽¹⁾		9
		18	19 ⁽¹⁾
		17	18 ⁽¹⁾
		16	17 ⁽¹⁾
		15	16 ⁽¹⁾
		14	15 ⁽¹⁾
		13	14
		12	13
		11	12
		10	11
		9	10
		8	9
		7	8
		6	7
		5	6
		4	5
		3.6	4
		3.5
		3
		2

Safari on iOS	Opera Mini	Android Browser	Blackberry Browser	Opera Mobile	Android Chrome	Android Firefox	IE Mobile	Android UC Browser	Samsung Internet	QQ Browser	Baidu Browser	KaiOS Browser
15	all ⁽²⁾	94	10 ⁽¹⁾	64	94	92	11	12.12 ⁽¹⁾	15.0	10.4	7.12	2.5
14.5-14.8		4.4.3-4.4.4 ⁽¹⁾	7	12.1 ⁽²⁾			10		14.0
14.0-14.4		4.4 ⁽¹⁾		12					13.0
13.4-13.7		4.2-4.3 ⁽¹⁾		11.5					12.0
Show all
13.3		4.1 ⁽¹⁾		11.1					11.1-11.2
13.2		4 ⁽¹⁾		11					10.1
13.0-13.1		3		10					9.2
12.2-12.5		2.3							8.2
12.0-12.1		2.2							7.2-7.4
11.3-11.4		2.1							6.2-6.4
11.0-11.2									5.0-5.4
10.3									4 ⁽¹⁾
10.0-10.2 ⁽¹⁾
9.3 ⁽¹⁾
9.0-9.2 ⁽¹⁾
8.1-8.4 ⁽¹⁾
8 ⁽¹⁾
7.0-7.1 ⁽¹⁾
6.0-6.1
5.0-5.1
4.2-4.3
4.0-4.1
3.2

Notes

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.

Does not match <input type="checkbox" checked> or <input type="radio" checked>
Does not match the default submit button of a form

Resources

Data by caniuse.com
Licensed under the Creative Commons Attribution License v4.0.
https://caniuse.com/css-default-pseudo