defer attribute for external scripts

The boolean defer attribute on script elements allows the external JavaScript file to run when the DOM is loaded, without delaying page load first.

Spec	https://html.spec.whatwg.org/multipage/scripting.html#attr-script-defer
Status	WHATWG Living Standard

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 ⁽¹⁾	93	91	93	14	78
8 ⁽¹⁾	92	90	92	13.1	77
Show all
7 ⁽¹⁾	91	89	91	13	76
6 ⁽¹⁾	90	88	90	12.1	75
5.5 ⁽¹⁾	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	70
	84	82	84	9.1	69
	83	81	83	9	68
	81	80	81	8	67
	80	79	80	7.1	66
	79	78	79	7	65
	18	77	78	6.1	64
	17	76	77	6	63
	16	75	76	5.1	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
		51	52		36
		50	51		35
		49	50		34
		48	49		33
		47	48		32
		46	47		31
		45	46		30
		44	45		29
		43	44		28
		42	43		27
		41	42		26
		40	41		25
		39	40		24
		38	39		23
		37	38		22
		36	37		21
		35	36		20
		34	35		19
		33	34		18
		32	33		17
		31	32		16
		30 ⁽²⁾	31		15
		29 ⁽²⁾	30		12.1
		28 ⁽²⁾	29		12
		27 ⁽²⁾	28		11.6
		26 ⁽²⁾	27		11.5
		25 ⁽²⁾	26		11.1
		24 ⁽²⁾	25		11
		23 ⁽²⁾	24		10.6
		22 ⁽²⁾	23		10.5
		21 ⁽²⁾	22		10.0-10.1
		20 ⁽²⁾	21		9.5-9.6
		19 ⁽²⁾	20		9
		18 ⁽²⁾	19
		17 ⁽²⁾	18
		16 ⁽²⁾	17
		15 ⁽²⁾	16
		14 ⁽²⁾	15
		13 ⁽²⁾	14
		12 ⁽²⁾	13
		11 ⁽²⁾	12
		10 ⁽²⁾	11
		9 ⁽²⁾	10
		8 ⁽²⁾	9
		7 ⁽²⁾	8
		6 ⁽²⁾	7
		5 ⁽²⁾	6
		4 ⁽²⁾	5
		3.6 ⁽²⁾	4
		3.5 ⁽²⁾
		3
		2

Notes

Partial support in older IE refers to a buggy implementation (see issue).
Deferred scripts may run after DOMContentLoaded - https://bugzilla.mozilla.org/show_bug.cgi?id=688580

IE < 10 may interleave execution of scripts, See the discussion.
Google Chrome does not defer scripts with the defer attribute when the page is served as XHTML (application/xhtml+xml) - Chromium Issue #611136, Chromium Issue #874749

Data by caniuse.com
Licensed under the Creative Commons Attribution License v4.0.
https://caniuse.com/script-defer