How to use this table
Each column does one job: the symbol column copies anywhere — chats, documents, email; the name column confirms you have the right one; the HTML column matters only when writing web pages — put the entity such as <code>&copy;</code> into the source and the browser renders ©. For everyday use, copy the symbol itself. Works the same on phones: long-press to select and copy.
Copyright & business marks
| 符号Symbol | 名称Name | HTML |
|---|---|---|
| © | 版权符Copyright | © / © |
| ® | 注册商标Registered trademark | ® / ® |
| ™ | 商标（未注册）Trademark | ™ / ™ |
| § | 章节号（法律条文）Section sign | § / § |
| ¶ | 段落符Pilcrow | ¶ / ¶ |
| • | 项目符号Bullet | • / • |
| … | 省略号（单字符）Ellipsis | … / … |
| — | 破折号（长横）Em dash | — / — |
| – | 连接号（短横）En dash | – / – |
® 和 ™ 的区别：® 只能用于已注册的商标，乱用涉嫌违法；™ 表示「我把这个当商标用」，未注册也能标。® is reserved for registered marks; ™ just signals trademark intent and needs no registration.
Maths & unit symbols
| 符号Symbol | 名称Name | HTML |
|---|---|---|
| ± | 正负号Plus-minus | ± / ± |
| × | 乘号Multiplication | × / × |
| ÷ | 除号Division | ÷ / ÷ |
| ° | 度数符Degree sign | ° / ° |
| ′ ″ | 分 / 秒（角度或英尺英寸）Prime / double prime | ′ / ″ |
| ‰ | 千分号Per mille | ‰ / ‰ |
| ℃ | 摄氏度（单字符）Degree Celsius | ℃ |
| ≈ ≠ ≤ ≥ | 约等、不等、小于等于、大于等于Approx / not equal / ≤ / ≥ | ≈ ≠ ≤ ≥ |
| ∞ √ ∑ ∏ ∫ | 无穷、根号、求和、求积、积分Infinity, root, sum, product, integral | ∞ √ ∑ ∏ ∫ |
| µ | 微（单位前缀）Micro prefix | µ / µ |
数学公式要成套用（上下标、分式、矩阵）时，对照 物理常量速查 和 三角函数表 更省事；网页里写复杂公式建议直接用 LaTeX 渲染而不是堆符号。For full formulas (fractions, matrices) prefer LaTeX rendering; symbol-by-symbol stacking breaks alignment.
Arrows
| 符号Symbol | 名称Name | HTML |
|---|---|---|
| ← → ↑ ↓ | 四向基础箭头Basic four directions | ← → ↑ ↓ |
| ↔ ↕ | 左右、上下双向Left-right / up-down | ↔ / ↕ |
| ⇐ ⇒ | 双线箭头（推导）Double arrows | ⇐ / ⇒ |
| ⇔ | 等价（双推导）If and only if | ↔ 的双线 ⇔ |
| ↻ | 循环 / 刷新Clockwise loop | ↻ |
| → 变体 | 长箭头、粗箭头（装饰用）Long & heavy variants | ⟶ / ➡ |
Five characters you must escape in HTML
Five characters carry syntax meaning in HTML, so showing the character itself requires an entity: & as &amp;, < as &lt;, > as &gt;, the double quote as &quot; inside attribute values, and the single quote as &#39; inside single-quoted attributes. Everything else is better pasted as the literal character — readable, searchable, smaller files. Reach for entities only when the character is untypeable and cross-platform display must be guaranteed.
Three ways to type what your keyboard lacks
First, the plain way: copy from this page. Second, your input method: Chinese pinyin IMEs offer a "u mode" or symbol panel (typing du often offers °; the panel has full maths and arrow categories); on Windows press Win+. for the emoji panel, on macOS Ctrl+Cmd+Space. Third, the system character map: Windows' Character Map or macOS' Character Viewer browses every glyph the system has. In code, prefer HTML entities or Unicode escapes (\u00B0) so a stray encoding mishap cannot eat the symbol.
FAQ
The symbol I copied turned into a question mark or an empty box.
A question mark usually means the target encoding lacks the character (legacy GBK misses several maths symbols); a box means the font has no glyph — the character is there but nothing can draw it. For encoding issues check the file encoding (the <a href="encoding-convert.html">encoding converter</a> handles this); for missing glyphs switch to a font that has them, or use the entity so the browser can fall back.
° and º look identical — same character?
No. ° is the degree sign (U+00B0); º is the masculine ordinal indicator (U+00BA) used in Spanish ordinals. Visually near-identical, but search engines and screen readers can tell — for temperatures and angles always use the degree sign, and copying from this table guarantees it.
In a web page, is the literal character or the entity better?
With UTF-8 declared, the literal character wins: the source stays readable, full-text searchable, and smaller. Entities earn their place in exactly three cases: the five syntax characters that must be escaped, team conventions demanding pure-ASCII sources, and pipelines where you cannot guarantee the file will not be transcoded wrongly. Otherwise use the character directly.