為了正確顯示 HTML 頁面，Web 瀏覽器必須知道要使用哪個(gè)字符集。

從 ASCII 到 UTF-8

ASCII 是第一個(gè)字符編碼標(biāo)準(zhǔn)。ASCII 定義了 128 種可以在互聯(lián)網(wǎng)上使用的字符：數(shù)字（0-9）、英文字母（A-Z）和一些特殊字符，比如：! $ + - ( ) @ < >。

ISO-8859-1 是 HTML 4 的默認(rèn)字符集。此字符集支持 256 個(gè)不同的字符代碼。HTML 4 同時(shí)支持 UTF-8。

ANSI（Windows-1252）是原始的 Windows 字符集。 ANSI 與 ISO-8859-1 相同，不同之處在于 ANSI 具有 32 個(gè)額外的字符。

HTML5 規(guī)范鼓勵(lì) Web 開發(fā)人員使用 UTF-8 字符集，該字符集涵蓋了世界上幾乎所有的字符和符號(hào)！

HTML charset 屬性

為了正確顯示 HTML 頁面，Web 瀏覽器必須了解頁面中使用的字符集。

這在??<meta>??標(biāo)簽中指定：

<meta charset="UTF-8">

字符集之間的差異

下表展示了上述字符集之間的區(qū)別：

Numb	ASCII	ANSI	8859	UTF-8	Description
32					space
33	!	!	!	!	exclamation mark
34	"	"	"	"	quotation mark
35	#	#	#	#	number sign
36	$	$	$	$	dollar sign
37	%	%	%	%	percent sign
38	&	&	&	&	ampersand
39	'	'	'	'	apostrophe
40	(	(	(	(	left parenthesis
41	)	)	)	)	right parenthesis
42	*	*	*	*	asterisk
43	+	+	+	+	plus sign
44	,	,	,	,	comma
45	-	-	-	-	hyphen-minus
46	.	.	.	.	full stop
47	/	/	/	/	solidus
48	0	0	0	0	digit zero
49	1	1	1	1	digit one
50	2	2	2	2	digit two
51	3	3	3	3	digit three
52	4	4	4	4	digit four
53	5	5	5	5	digit five
54	6	6	6	6	digit six
55	7	7	7	7	digit seven
56	8	8	8	8	digit eight
57	9	9	9	9	digit nine
58	:	:	:	:	colon
59	;	;	;	;	semicolon
60	<	<	<	<	less-than sign
61	=	=	=	=	equals sign
62	>	>	>	>	greater-than sign
63	?	?	?	?	question mark
64	@	@	@	@	commercial at
65	A	A	A	A	Latin capital letter A
66	B	B	B	B	Latin capital letter B
67	C	C	C	C	Latin capital letter C
68	D	D	D	D	Latin capital letter D
69	E	E	E	E	Latin capital letter E
70	F	F	F	F	Latin capital letter F
71	G	G	G	G	Latin capital letter G
72	H	H	H	H	Latin capital letter H
73	I	I	I	I	Latin capital letter I
74	J	J	J	J	Latin capital letter J
75	K	K	K	K	Latin capital letter K
76	L	L	L	L	Latin capital letter L
77	M	M	M	M	Latin capital letter M
78	N	N	N	N	Latin capital letter N
79	O	O	O	O	Latin capital letter O
80	P	P	P	P	Latin capital letter P
81	Q	Q	Q	Q	Latin capital letter Q
82	R	R	R	R	Latin capital letter R
83	S	S	S	S	Latin capital letter S
84	T	T	T	T	Latin capital letter T
85	U	U	U	U	Latin capital letter U
86	V	V	V	V	Latin capital letter V
87	W	W	W	W	Latin capital letter W
88	X	X	X	X	Latin capital letter X
89	Y	Y	Y	Y	Latin capital letter Y
90	Z	Z	Z	Z	Latin capital letter Z
91	[	[	[	[	left square bracket
92	\	\	\	\	reverse solidus
93	]	]	]	]	right square bracket
94	^	^	^	^	circumflex accent
95	_	_	_	_	low line
96	`	`	`	`	grave accent
97	a	a	a	a	Latin small letter a
98	b	b	b	b	Latin small letter b
99	c	c	c	c	Latin small letter c
100	d	d	d	d	Latin small letter d
101	e	e	e	e	Latin small letter e
102	f	f	f	f	Latin small letter f
103	g	g	g	g	Latin small letter g
104	h	h	h	h	Latin small letter h
105	i	i	i	i	Latin small letter i
106	j	j	j	j	Latin small letter j
107	k	k	k	k	Latin small letter k
108	l	l	l	l	Latin small letter l
109	m	m	m	m	Latin small letter m
110	n	n	n	n	Latin small letter n
111	o	o	o	o	Latin small letter o
112	p	p	p	p	Latin small letter p
113	q	q	q	q	Latin small letter q
114	r	r	r	r	Latin small letter r
115	s	s	s	s	Latin small letter s
116	t	t	t	t	Latin small letter t
117	u	u	u	u	Latin small letter u
118	v	v	v	v	Latin small letter v
119	w	w	w	w	Latin small letter w
120	x	x	x	x	Latin small letter x
121	y	y	y	y	Latin small letter y
122	z	z	z	z	Latin small letter z
123	{	{	{	{	left curly bracket
124	|	|	|	|	vertical line
125	}	}	}	}	right curly bracket
126	~	~	~	~	tilde
127	DEL
128		€			euro sign
129					NOT USED
130		?			single low-9 quotation mark
131		?			Latin small letter f with hook
132		?			double low-9 quotation mark
133		…			horizontal ellipsis
134		?			dagger
135		?			double dagger
136		?			modifier letter circumflex accent
137		‰			per mille sign
138		?			Latin capital letter S with caron
139		?			single left-pointing angle quotation mark
140		?			Latin capital ligature OE
141					NOT USED
142		?			Latin capital letter Z with caron
143					NOT USED
144					NOT USED
145		‘			left single quotation mark
146		’			right single quotation mark
147		“			left double quotation mark
148		”			right double quotation mark
149		?			bullet
150		–			en dash
151		—			em dash
152		?			small tilde
153		?			trade mark sign
154		?			Latin small letter s with caron
155		?			single right-pointing angle quotation mark
156		?			Latin small ligature oe
157					NOT USED
158		?			Latin small letter z with caron
159		?			Latin capital letter Y with diaeresis
160					no-break space
161		?	?	?	inverted exclamation mark
162		￠	￠	￠	cent sign
163		￡	￡	￡	pound sign
164		¤	¤	¤	currency sign
165		￥	￥	￥	yen sign
166		|	|	|	broken bar
167		§	§	§	section sign
168		¨	¨	¨	diaeresis
169		?	?	?	copyright sign
170		a	a	a	feminine ordinal indicator
171		?	?	?	left-pointing double angle quotation mark
172		?	?	?	not sign
173		-	-	-	soft hyphen
174		?	?	?	registered sign
175		ˉ	ˉ	ˉ	macron
176		°	°	°	degree sign
177		±	±	±	plus-minus sign
178		2	2	2	superscript two
179		3	3	3	superscript three
180		′	′	′	acute accent
181		μ	μ	μ	micro sign
182		?	?	?	pilcrow sign
183		·	·	·	middle dot
184		?	?	?	cedilla
185		1	1	1	superscript one
186		o	o	o	masculine ordinal indicator
187		?	?	?	right-pointing double angle quotation mark
188		?	?	?	vulgar fraction one quarter
189		?	?	?	vulgar fraction one half
190		?	?	?	vulgar fraction three quarters
191		?	?	?	inverted question mark
192		à	à	à	Latin capital letter A with grave
193		á	á	á	Latin capital letter A with acute
194		?	?	?	Latin capital letter A with circumflex
195		?	?	?	Latin capital letter A with tilde
196		?	?	?	Latin capital letter A with diaeresis
197		?	?	?	Latin capital letter A with ring above
198		?	?	?	Latin capital letter AE
199		?	?	?	Latin capital letter C with cedilla
200		è	è	è	Latin capital letter E with grave
201		é	é	é	Latin capital letter E with acute
202		ê	ê	ê	Latin capital letter E with circumflex
203		?	?	?	Latin capital letter E with diaeresis
204		ì	ì	ì	Latin capital letter I with grave
205		í	í	í	Latin capital letter I with acute
206		?	?	?	Latin capital letter I with circumflex
207		?	?	?	Latin capital letter I with diaeresis
208		D	D	D	Latin capital letter Eth
209		?	?	?	Latin capital letter N with tilde
210		ò	ò	ò	Latin capital letter O with grave
211		ó	ó	ó	Latin capital letter O with acute
212		?	?	?	Latin capital letter O with circumflex
213		?	?	?	Latin capital letter O with tilde
214		?	?	?	Latin capital letter O with diaeresis
215		×	×	×	multiplication sign
216		?	?	?	Latin capital letter O with stroke
217		ù	ù	ù	Latin capital letter U with grave
218		ú	ú	ú	Latin capital letter U with acute
219		?	?	?	Latin capital letter U with circumflex
220		ü	ü	ü	Latin capital letter U with diaeresis
221		Y	Y	Y	Latin capital letter Y with acute
222		T	T	T	Latin capital letter Thorn
223		?	?	?	Latin small letter sharp s
224		à	à	à	Latin small letter a with grave
225		á	á	á	Latin small letter a with acute
226		a	a	a	Latin small letter a with circumflex
227		?	?	?	Latin small letter a with tilde
228		?	?	?	Latin small letter a with diaeresis
229		?	?	?	Latin small letter a with ring above
230		?	?	?	Latin small letter ae
231		?	?	?	Latin small letter c with cedilla
232		è	è	è	Latin small letter e with grave
233		é	é	é	Latin small letter e with acute
234		ê	ê	ê	Latin small letter e with circumflex
235		?	?	?	Latin small letter e with diaeresis
236		ì	ì	ì	Latin small letter i with grave
237		í	í	í	Latin small letter i with acute
238		?	?	?	Latin small letter i with circumflex
239		?	?	?	Latin small letter i with diaeresis
240		e	e	e	Latin small letter eth
241		?	?	?	Latin small letter n with tilde
242		ò	ò	ò	Latin small letter o with grave
243		ó	ó	ó	Latin small letter o with acute
244		?	?	?	Latin small letter o with circumflex
245		?	?	?	Latin small letter o with tilde
246		?	?	?	Latin small letter o with diaeresis
247		÷	÷	÷	division sign
248		?	?	?	Latin small letter o with stroke
249		ù	ù	ù	Latin small letter u with grave
250		ú	ú	ú	Latin small letter u with acute
251		?	?	?	Latin small letter with circumflex
252		ü	ü	ü	Latin small letter u with diaeresis
253		y	y	y	Latin small letter y with acute
254		t	t	t	Latin small letter thorn
255		?	?	?	Latin small letter y with diaeresis

ASCII 字符集

ASCII 使用 0 到 31（以及 127）之間的值作為控制字符。

ASCII 使用 32 到 126 的值表示字母、數(shù)字和符號(hào)。

ASCII 不使用 128 到 255 之間的值。

ANSI 字符集 (Windows-1252)

對(duì)于 0 到 127 的值，ANSI 與 ASCII 相同。

ANSI 有一組專有的字符，其值從 128 到 159。

對(duì)于 160 到 255 的值，ANSI 與 UTF-8 相同。

ISO-8859-1 字符集

對(duì)于 0 到 127 的值，8859-1 與 ASCII 相同。

8859-1 不使用 128 到 159 之間的值。

對(duì)于從 160 到 255 的值，8859-1 與 UTF-8 相同。

UTF-8 字符集

對(duì)于 0 到 127 的值，UTF-8 與 ASCII 相同。

UTF-8 不使用 12 8到 159 之間的值。

對(duì)于 160 到 255 之間的值，UTF-8 與 ANSI 和 8859-1 相同。

UTF-8 從值 256 繼續(xù)，包含超過 10000 個(gè)不同字符。

如需深入研究，請(qǐng)閱讀我們完整的 HTML 字符集參考手冊(cè)。

@charset CSS 規(guī)則

您可以使用 CSS @charset 規(guī)則來指定樣式表中使用的字符編碼：

實(shí)例

將樣式表的編碼設(shè)置為 Unicode UTF-8：

@charset "UTF-8";