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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
			108
		107	107	TP
		106	106	16.1
11	105	105	105	16.0	91
10	104	104	104	15.6	90
9 ⁽¹⁾	103	103	103	15.5	89
8 ⁽¹⁾	102	102	102	15.4	88
Show all
7 ⁽¹⁾	101	101	101	15.2-15.3	87
6 ⁽¹⁾	100	100	100	15.1	86
5.5 ⁽¹⁾	99	99	99	15	85
	98	98	98	14.1	84
	97	97	97	14	83
	96	96	96	13.1	82
	95	95	95	13	81
	94	94	94	12.1	80
	93	93	93	12	79
	92	92	92	11.1	78
	91	91	91	11	77
	90	90	90	10.1	76
	89	89	89	10	75
	88	88	88	9.1	74
	87	87	87	9	73
	86	86	86	8	72
	85	85	85	7.1	71
	84	84	84	7	70
	83	83	83	6.1	69
	81	82	81	6	68
	80	81	80	5.1	67
	79	80	79	5	66
	18	79	78	4	65
	17	78	77	3.2	64
	16	77	76	3.1	63
	15	76	75		62
	14	75	74		60
	13	74	73		58
	12	73	72		57
		72	71		56
		71	70		55
		70	69		54
		69	68		53
		68	67		52
		67	66		51
		66	65		50
		65	64		49
		64	63		48
		63	62		47
		62	61		46
		61	60		45
		60	59		44
		59	58		43
		58	57		42
		57	56		41
		56	55		40
		55	54		39
		54	53		38
		53	52		37
		52	51		36
		51	50		35
		50	49		34
		49	48		33
		48	47		32
		47	46		31
		46	45		30
		45	44		29
		44	43		28
		43	42		27
		42	41		26
		41	40		25
		40	39		24
		39	38		23
		38	37		22
		37	36		21
		36	35		20
		35	34		19
		34	33		18
		33	32		17
		32	31		16
		31	30		15
		30 ⁽²⁾	29		12.1
		29 ⁽²⁾	28		12
		28 ⁽²⁾	27		11.6
		27 ⁽²⁾	26		11.5
		26 ⁽²⁾	25		11.1
		25 ⁽²⁾	24		11
		24 ⁽²⁾	23		10.6
		23 ⁽²⁾	22		10.5
		22 ⁽²⁾	21		10.0-10.1
		21 ⁽²⁾	20		9.5-9.6
		20 ⁽²⁾	19		9
		19 ⁽²⁾	18
		18 ⁽²⁾	17
		17 ⁽²⁾	16
		16 ⁽²⁾	15
		15 ⁽²⁾	14
		14 ⁽²⁾	13
		13 ⁽²⁾	12
		12 ⁽²⁾	11
		11 ⁽²⁾	10
		10 ⁽²⁾	9
		9 ⁽²⁾	8
		8 ⁽²⁾	7
		7 ⁽²⁾	6
		6 ⁽²⁾	5
		5 ⁽²⁾	4
		4 ⁽²⁾
		3.6 ⁽²⁾
		3.5 ⁽²⁾
		3
		2

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