前言
一些字符在 HTML 中是预留的，拥有特殊的含义，比如小于号‘<’用于定义 HTML 标签的开始。如果我们希望浏览器正确地显示这些字符，我们必须在 HTML 源码中插入字符实体。
字符实体有三部分：一个和号‘&’和一个实体名称（或者一个‘#’ 和一个实体编号），以及一个分号‘;’。
要在 HTML 文档中显示小于号，我们需要这样写：< 或者‘<’最后的效果则是<。
使用实体名称而不是实体编号的好处在于，名称相对来说更容易记忆。而这么做的坏处是，并不是所有的浏览器都支持最新的实体名称，然而几乎所有的浏览器对实体编号的支持都很好。
注意：实体对大小写敏感。
一、HTML 特殊字符
HTML实体 字符 实体编号 描述 CSS (ISO) JS (Octal) " " " 引号 \0022 \42 # # # 数字符号 \0023 \43 $ $ $ 美元符号 \0024 \44 % % % 百分号 \0025 \45 & & & 和号 \0026 \46 ' ' ' 撇号 \0027 \47 ( ( ( 左括号 \0028 \50 ) ) ) 右括号 \0029 \51 * * * 星号 \002a \52 + + + 加号 \002b \53 , , , 逗号 \002c \54 − - - 连字符减号 \002d \55 . . . 句号 \002e \56 / / / 固相线 \002f \57 : : : 冒号 \003a \72 ; ; ; 分号 \003b \73 < < < 少于 \003c \74 = = = 等于 \003d \75 > > > 大于号 \003e \76 ? ? ? 问号 \003f \77 @ @ @ 在标志处 \0040 \100 [ [ [ 左方括号 \005b \133 \ \ \ 反斜杠 \005c \134 ] ] ] 右方括号 \005d \135 ^ ^ ^ 抑扬顿挫 \005e \136 _ _ _ 低线 \005f \137 ` ` ` 重音 \0060 \u0060 { { { 左大括号 \007b \173 | | | 竖线 \007c \174 } } } 右大括号 \007d \175 ~ ~ 波浪号 \007e \176
二、HTML 拉丁语
HTML实体 字符 实体编号 描述 CSS (ISO) JS (Octal)   no-break space \00a0 \240 ¡ ¡ ¡ inverted exclamation mark \00a1 \241 ¢ ¢ ¢ cent sign \00a2 \242 £ £ £ pound sterling sign \00a3 \243 ¤ ¤ ¤ general currency sign \00a4 \244 ¥ ¥ ¥ yen sign \00a5 \245 ₹ ₹ ₹ Indian Rupee (INR) sign \20B9 \u20B9 ¦ ¦ ¦ broken (vertical) bar \00a6 \246 § § § section sign \00a7 \247 ¨ ¨ ¨ umlaut (dieresis) \00a8 \250 © © © copyright sign \00a9 \251 ª ª ª ordinal indicator, feminine \00aa \252 « « « angle quotation mark, left \00ab \253 ¬ ¬ ¬ not sign \00ac \254 ­ ­ soft hyphen \00ad \255 ® ® ® registered sign \00ae \256 ¯ ¯ ¯ macron \00af \257 ° ° ° degree sign \00b0 \260 ± ± ± plus-or-minus sign \00b1 \261 ² ² ² superscript two \00b2 \262 ³ ³ ³ superscript three \00b3 \263 ´ ´ ´ acute accent \00b4 \264 µ µ µ micro sign \00b5 \265 ¶ ¶ ¶ pilcrow (paragraph sign) \00b6 \266 · · · middle dot \00b7 \267 ¸ ¸ ¸ cedilla \00b8 \270 ¹ ¹ ¹ superscript one \00b9 \271 º º º ordinal indicator, masculine \00ba \272 » » » angle quotation mark, right \00bb \273 ¼ ¼ ¼ fraction one-quarter \00bc \274 ½ ½ ½ fraction one-half \00bd \275 ¾ ¾ ¾ fraction three-quarters \00be \276 ¿ ¿ ¿ inverted question mark \00bf \277 À À À capital A, grave accent \00c0 \300 Á Á Á capital A, acute accent \00c1 \301    ; capital A, circumflex accent \00c2 \302 à à à capital A, tilde \00c3 \303 Ä Ä Ä capital A, dieresis or umlaut mark \00c4 \304 Å Å Å capital A, ring \00c5 \305 Æ Æ Æ capital AE diphthong (ligature) \00c6 \306 Ç Ç Ç capital C, cedilla \00c7 \307 È È È capital E, grave accent \00c8 \310 É É É capital E, acute accent \00c9 \311 Ê Ê Ê capital E, circumflex accent \00ca \312 Ë Ë Ë capital E, dieresis or umlaut mark \00cb \313 Ì Ì Ì capital I, grave accent \00cc \314 Í Í Í capital I, acute accent \00cd \315 Î Î Î capital I, circumflex accent \00ce \316 Ï Ï Ï capital I, dieresis or umlaut mark \00cf \317 Ð Ð Ð capital Eth, Icelandic \00d0 \320 Ñ Ñ Ñ capital N, tilde \00d1 \321 Ò Ò Ò capital O, grave accent \00d2 \322 Ó Ó Ó capital O, acute accent \00d3 \323 Ô Ô Ô capital O, circumflex accent \00d4 \324 Õ Õ Õ capital O, tilde \00d5 \325 Ö Ö Ö capital O, dieresis or umlaut mark \00d6 \326 × × × multiply sign \00d7 \327 Ø Ø Ø capital O, slash \00d8 \330 Ù Ù Ù capital U, grave accent \00d9 \331 Ú Ú Ú capital U, acute accent \00da \332 Û Û Û capital U, circumflex accent \00db \333 Ü Ü Ü capital U, dieresis or umlaut mark \00dc \334 Ý Ý Ý capital Y, acute accent \00dd \335 Þ Þ Þ capital THORN, Icelandic \00de \336 ß ß ß small sharp s, German (sz ligature) \00df \337 à à à small a, grave accent \00e0 \340 á á á small a, acute accent \00e1 \341 â â â small a, circumflex accent \00e2 \342 ã ã ã small a, tilde \00e3 \343 ä ä ä small a, dieresis or umlaut mark \00e4 \344 å å å small a, ring \00e5 \345 æ æ æ small ae diphthong (ligature) \00e6 \346 ç ç ç small c, cedilla \00e7 \347 è è è small e, grave accent \00e8 \350 é é é small e, acute accent \00e9 \351 ê ê ê small e, circumflex accent \00ea \352 ë ë ë small e, dieresis or umlaut mark \00eb \353 ì ì ì small i, grave accent \00ec \354 í í í small i, acute accent \00ed \355 î î î small i, circumflex accent \00ee \356 ï ï ï small i, dieresis or umlaut mark \00ef \357 ð ð ð small eth, Icelandic \00f0 \360 ñ ñ ñ small n, tilde \00f1 \361 ò ò ò small o, grave accent \00f2 \362 ó ó ó small o, acute accent \00f3 \363 ô ô ô small o, circumflex accent \00f4 \364 õ õ õ small o, tilde \00f5 \365 ö ö ö small o, dieresis or umlaut mark \00f6 \366 ÷ ÷ ÷ divide sign \00f7 \367 ø ø ø small o, slash \00f8 \370 ù ù ù small u, grave accent \00f9 \371 ú ú ú small u, acute accent \00fa \372 û û û small u, circumflex accent \00fb \373 ü ü ü small u, dieresis or umlaut mark \00fc \374 ý ý ý small y, acute accent \00fd \375 þ þ þ small thorn, Icelandic \00fe \376 ÿ ÿ ÿ small y, dieresis or umlaut mark \00ff \377 Œ Œ Œ latin capital ligature oe \0152 \u0152 œ œ œ latin small ligature oe \0153 \u0153 Š Š Š latin capital letter s with caron \0160 \u0160 š š š latin small letter s with caron \0161 \u0161 Ÿ Ÿ Ÿ latin capital letter y with diaeresis \0178 \u0178 ƒ ƒ ƒ latin small f with hook \0192 \u0192
三、HTML 希腊语
HTML实体 字符 实体编号 描述 CSS (ISO) JS (Octal) Α Α Α greek capital letter alpha \0391 \u0391 Β Β Β greek capital letter beta \0392 \u0392 Γ Γ Γ greek capital letter gamma \0393 \u0395 Δ Δ Δ greek capital letter delta \0394 \u0394 Ε Ε Ε greek capital letter epsilon \0395 \u0395 Ζ Ζ Ζ greek capital letter zeta \0396 \u0396 Η Η Η greek capital letter eta \0397 \u0397 Θ Θ Θ greek capital letter theta \0398 \u0398 Ι Ι Ι greek capital letter iota \0399 \u0399 Κ Κ Κ greek capital letter kappa \039a \u039a Λ Λ Λ greek capital letter lambda \039b \u039b Μ Μ Μ greek capital letter mu \039c \u039c Ν Ν Ν greek capital letter nu \039d \u039D Ξ Ξ Ξ greek capital letter xi \039e \u039e Ο Ο Ο greek capital letter omicron \039f \u039f Π Π Π greek capital letter pi \03a0 \u03a0 Ρ Ρ Ρ greek capital letter rho \03a1 \u03a1 Σ Σ Σ greek capital letter sigma \03a3 \u03A3 Τ Τ Τ greek capital letter tau \03a4 \u03A4 Υ Υ Υ greek capital letter upsilon \03a5 \u03A5 Φ Φ Φ greek capital letter phi \03a6 \u03A6 Χ Χ Χ greek capital letter chi \03a7 \u03A7 Ψ Ψ Ψ greek capital letter psi \03a8 \u03A8 Ω Ω Ω greek capital letter omega \03a9 \u03A9 α α α greek small letter alpha \03b1 \u03b1 β β β greek small letter beta \03b2 \u03b2 γ γ γ greek small letter gamma \03b3 \u03b3 δ δ δ greek small letter delta \03b4 \u03b4 ε ε ε greek small letter epsilon \03b5 \u03b5 ζ ζ ζ greek small letter zeta \03b6 \u03b6 η η η greek small letter eta \03b7 \u03b7 θ θ θ greek small letter theta \03b8 \u03b8 ι ι ι greek small letter iota \03b9 \u03b9 κ κ κ greek small letter kappa \03ba \u03ba λ λ λ greek small letter lambda \03bb \u03bb μ μ μ greek small letter mu \03bc \u03bc ν ν ν greek small letter nu \03bd \u03bd ξ ξ ξ greek small letter xi \03be \u03be ο ο ο greek small letter omicron \03bf \u03bf π π π greek small letter pi \03c0 \u03c0 ρ ρ ρ greek small letter rho \03c1 \u03c1 ς ς ς greek small letter final sigma \03C2 \u03c2 σ σ σ greek small letter sigma \03C3 \u03c3 τ τ τ greek small letter tau \03C4 \u03c4 υ υ υ greek small letter upsilon \03C5 \u03c5 φ φ φ greek small letter phi \03C6 \03c6 χ χ χ greek small letter chi \03C7 \u03c7 ψ ψ ψ greek small letter psi \03C8 \u03c8 ω ω ω greek small letter omega \03C9 \u03c9 ϑ ϑ ϑ greek small letter theta symbol \03D1 \u03D1 ϒ ϒ ϒ greek upsilon with hook symbol \03D2 \u03D2 ϖ ϖ ϖ greek pi symbol \03D6 \u03D6
四、HTML 标点符号
HTML实体 字符 实体编号 描述 CSS (ISO) JS (Octal)     en space \2002 \u2002     em space \2003 \u2003     thin space \2009 \u2009 ‌ ‌ zero width non-joiner \200C \u200C ‍ ‍ zero width joiner \200D \u200d ‎ ‎ left-to-right mark \200E \u200e ‏ ‏ right-to-left mark \200F \u200f – – – en dash \2013 \u2013 — — — em dash \2014 \u2014 ‘ ‘ ‘ left single quotation mark \2018 \u2018 ’ ’ ’ right single quotation mark \2019 \u2019 ‚ ‚ ‚ single low-9 quotation mark \201A \u201a “ “ “ left double quotation mark \201C \u201c ” ” ” right double quotation mark \201D \u201d „ „ „ double low-9 quotation mark \201E \u201e † † † dagger \2020 \u2020 ‡ ‡ ‡ double dagger \2021 \u2021 ‰ ‰ ‰ per mille sign \2030 \u2030 ‹ ‹ ‹ single left-pointing angle quotation mark \2039 \u2039 › › › single right-pointing angle quotation mark \203A \u203a • • • bullet, aka. black small circle \2022 \u2219 … … … horizontal ellipsis, aka three dot leader \2026 \u2026 ′ ′ ′ prime, aka minutes, aka feet \2032 \u2032 ″ ″ ″ double prime, aka seconds, aka inches \2033 \u2033 ‾ ‾ ‾ overline, aka spacing overscore \203E \u203e ⁄ ⁄ ⁄ fraction slash \2044 \u8260
五、HTML 箭头
HTML实体 字符 实体编号 描述 CSS (ISO) JS (Octal) ← ← ← 向左箭头 \2190 \u2190 ↑ ↑ ↑ 向上箭头 \2191 \u2191 → → → 向右箭头 \2192 \u2192 ↓ ↓ ↓ 向下箭头 \2193 \u2193 ↔ ↔ ↔ 左右双向箭头 \2194 \u2194 ↵ ↵ ↵ 回车箭头 \21B5 \u21b5 ⇐ ⇐ ⇐ 向左的双箭头 \21D0 \u21d0 ⇑ ⇑ ⇑ 向上的双箭头 \21D1 \u21d1 ⇒ ⇒ ⇒ 向右的双箭头 \21D2 \u21d2 ⇓ ⇓ ⇓ 向下的双箭头 \21D3 \ud1d3 ⇔ ⇔ ⇔ 左右双向的双箭头 \21D4 \u21d4 ◄ ◄ 向左的黑色实心箭头 \25C0 \u25c0 ► ► 向右的黑色实心箭头 \25b6 \u25b6 ▲ ▲ 向上的黑色实心箭头 \25b2 \25b2 ▼ ▼ 向下的黑色实心箭头 \25bc \25bc
六、HTML 数学运算符
HTML实体 字符 实体编号 描述 CSS (ISO) JS (Octal) ∀ ∀ ∀ for all \2200 \u2200 ∂ ∂ ∂ partial differential \2202 \u2202 ∃ ∃ ∃ there exists \2203 \u2203 ∅ ∅ ∅ empty set, aka null set, aka diameter \2205 \u2205 ∇ ∇ ∇ nabla, aka bakad difference \2207 \u2207 ∈ ∈ ∈ element of \2208 \u2208 ∉ ∉ ∉ not an element of \2209 \u2209 ∋ ∋ ∋ contains as member \220B \u220b ∏ ∏ ∏ n-ary product, aka product sign \220F \u03a0 ∑ ∑ ∑ n-ary sumation \2211 \u03a3 − − − minus sign \2212 \u2212 ∗ ∗ ∗ asterisk operator \2217 \u2217 √ √ √ square root, aka radical sign \221A \u221a ∝ ∝ ∝ proportional to \221D \u221d ∞ ∞ ∞ infinity \221E \u221e ∠ ∠ ∠ angle \2220 \u2220 ∧ ⊥ ⊥ logical and, aka wedge \2227 \u2227 ∨ ⊦ ⊦ logical or, aka vee \2228 \u2228 ∩ ∩ ∩ intersection, aka cap \2229 \u2229 ∪ ∪ ∪ union, aka cup \222A \u222a ∫ ∫ ∫ integral \222B \u222b ∴ ∴ ∴ therefore \2234 \u2234 ∼ ∼ ∼ tilde \223C \u223c ≅ ≅ ≅ approximately equal to \2245 \u2245 ≈ ≈ ≈ almost equal to, aka asymptotic to \2248 \u2248 ≠ ≠ ≠ not equal to \2260 \u2260 ≡ ≡ ≡ identical to \2261 \u2261 ≤ ≤ ≤ less-than or equal to \2264 \u2264 ≥ ≥ ≥ greater-than or equal to \2265 \u2265 ⊂ ⊂ ⊂ subset of \2282 \u2282 ⊃ ⊃ ⊃ superset of \2283 \u2283 ⊄ ⊄ ⊄ not a subset of \2284 \u2284 ⊆ ⊆ ⊆ subset of or equal to \2286 \u2286 ⊇ ⊇ ⊇ superset of or equal to \2287 \u2287 ⊕ ⊕ ⊕ circled plus, aka direct sum \2295 \u2295 ⊗ ⊗ ⊗ circled times, aka vector product \2297 \u2297 ⊥ ⊥ ⊥ up tack \22A5 \u22a5 ⋅ ⋅ ⋅ dot operator \22C5 \u22c5
七、HTML 其他
HTML实体 字符 实体编号 描述 CSS (ISO) JS (Octal) ◊ ◊ ◊ 菱形 \25CA \u25ca ♠ ♠ ♠ 黑桃 \2660 \u2660 ♣ ♣ ♣ 梅花 \2663 \u2663 ♥ ♥ ♥ 黑心套装，又名情人节 \2665 \u2665 ♦ ♦ ♦ 方块 \2666 \u2666 ℘ ℘ ℘ 不知道怎么描述，看符号吧 \2118 \u2118 ℑ ℑ ℑ 不知道怎么描述，看符号吧 \2111 \u2111 ℜ ℜ ℜ 不知道怎么描述，看符号吧 \211C \u211c ™ ™ ™ 商标标志 \2122 \u2122 ℵ ℵ ℵ 不知道怎么描述，看符号吧 \2135 \u ˆ ˆ 向上的尖括号 \02c6 \u02c6 ˜ ˜ 小波浪 \02dc \u02dc
