CSS @when / @else conditional rules

Syntax allowing CSS conditions (like media and support queries) to be written more simply, as well as making it possibly to write mutually exclusive rules using @else statements.

Spec	https://www.w3.org/TR/css-conditional-5/#when-rule
Status	W3C Working Draft

IE	Edge	Firefox	Chrome	Safari	Opera
			103
		100	102
		99	101	TP
11	99	98	100	15.4	83
10	98	97	99	15.2-15.3	82
9	97	96	98	15.1	81
8	96	95	97	15	80
Show all
7	95	94	96	14.1	79
6	94	93	95	14	78
5.5	93	92	94	13.1	77
	92	91	93	13	76
	91	90	92	12.1	75
	90	89	91	12	74
	89	88	90	11.1	73
	88	87	89	11	72
	87	86	88	10.1	71
	86	85	87	10	70
	85	84	86	9.1	69
	84	83	85	9	68
	83	82	84	8	67
	81	81	83	7.1	66
	80	80	81	7	65
	79	79	80	6.1	64
	18	78	79	6	63
	17	77	78	5.1	62
	16	76	77	5	60
	15	75	76	4	58
	14	74	75	3.2	57
	13	73	74	3.1	56
	12	72	73		55
		71	72		54
		70	71		53
		69	70		52
		68	69		51
		67	68		50
		66	67		49
		65	66		48
		64	65		47
		63	64		46
		62	63		45
		61	62		44
		60	61		43
		59	60		42
		58	59		41
		57	58		40
		56	57		39
		55	56		38
		54	55		37
		53	54		36
		52	53		35
		51	52		34
		50	51		33
		49	50		32
		48	49		31
		47	48		30
		46	47		29
		45	46		28
		44	45		27
		43	44		26
		42	43		25
		41	42		24
		40	41		23
		39	40		22
		38	39		21
		37	38		20
		36	37		19
		35	36		18
		34	35		17
		33	34		16
		32	33		15
		31	32		12.1
		30	31		12
		29	30		11.6
		28	29		11.5
		27	28		11.1
		26	27		11
		25	26		10.6
		24	25		10.5
		23	24		10.0-10.1
		22	23		9.5-9.6
		21	22		9
		20	21
		19	20
		18	19
		17	18
		16	17
		15	16
		14	15
		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
15.4	all	99	10	64	100	98	11	12.12	16.0	10.4	7.12	2.5
15.2-15.3		4.4.3-4.4.4	7	12.1			10		15.0
15.0-15.1		4.4		12					14.0
14.5-14.8		4.2-4.3		11.5					13.0
Show all
14.0-14.4		4.1		11.1					12.0
13.4-13.7		4		11					11.1-11.2
13.3		3		10					10.1
13.2		2.3							9.2
13.0-13.1		2.2							8.2
12.2-12.5		2.1							7.2-7.4
12.0-12.1									6.2-6.4
11.3-11.4									5.0-5.4
11.0-11.2									4
10.3
10.0-10.2
9.3
9.0-9.2
8.1-8.4
8
7.0-7.1
6.0-6.1
5.0-5.1
4.2-4.3
4.0-4.1
3.2

Notes

Resources

• Blog post: Extending CSS when/else chains: A first look
• Chrome support bug
• Firefox support bug
• WebKit support bug