HTML and text tools
HTML Entity Encoder / Decoder
Encode text into HTML entities, decode entities back to readable characters, and copy common named, numeric, and hexadecimal references.
The conversion is performed in your browser. Pasted text is not uploaded.
HTML Entity Reference
| Char | Named | Numeric | Description |
|---|---|---|---|
| & | Ampersand | ||
| < | Less than | ||
| > | Greater than | ||
| " | Double quote | ||
| ' | Apostrophe | ||
| [ ] | Non-breaking space | ||
| © | Copyright | ||
| ® | Registered | ||
| ™ | Trademark | ||
| ¢ | Cent | ||
| £ | Pound | ||
| ¥ | Yen | ||
| € | Euro | ||
| ° | Degree | ||
| ± | Plus-minus | ||
| × | Multiplication | ||
| ÷ | Division | ||
| ≠ | Not equal | ||
| ≤ | Less or equal | ||
| ≥ | Greater or equal | ||
| ∞ | Infinity | ||
| ∑ | Summation | ||
| √ | Square root | ||
| ← | Left arrow | ||
| ↑ | Up arrow | ||
| → | Right arrow | ||
| ↓ | Down arrow | ||
| ↔ | Left-right arrow | ||
| • | Bullet | ||
| … | Ellipsis | ||
| – | En dash | ||
| — | Em dash | ||
| ‘ | Left single quote | ||
| ’ | Right single quote | ||
| “ | Left double quote | ||
| ” | Right double quote | ||
| « | Left guillemet | ||
| » | Right guillemet | ||
| ¼ | One quarter | ||
| ½ | One half | ||
| ¾ | Three quarters | ||
| ¿ | Inverted question | ||
| ¡ | Inverted exclamation | ||
| ¶ | Paragraph | ||
| § | Section | ||
| † | Dagger | ||
| ‡ | Double dagger | ||
| ♠ | Spade | ||
| ♣ | Club | ||
| ♥ | Heart | ||
| ♦ | Diamond |
よくある質問
HTML エンティティとは何ですか？
&、<、> のように、HTML で特別な意味を持つ文字や、直接入力できない文字を安全に表示するための表記法です。& で始まり ; で終わります。XSS 攻撃を防ぐためにも重要です。
「特殊文字のみ」と「全文字」の違いは？
「特殊文字のみ」は HTML 構文に影響する & < > " ' の5文字だけをエンコードします。「全文字」は非 ASCII 文字も含めてすべてエンティティに変換します。通常は「特殊文字のみ」で十分です。
名前付きエンティティと数値エンティティの違いは？
名前付き（&copy; など）は可読性が高く、数値（© など）はすべてのブラウザで確実にサポートされます。どちらも同じ文字を表示しますが、HTML5 では名前付きを推奨しています。
関連ツール
Encode reserved characters
Convert symbols such as <, >, &, quotes, and currency marks into HTML-safe text.
Decode pasted entities
Turn named, numeric, and hexadecimal entity references back into readable characters.
Example snippets
Try <div>, ©, or © to compare named and numeric forms.
Entity Encoding Guide
Reserved HTML characters
Characters such as less-than and ampersand can change markup meaning, so they should be encoded when displayed as text.
Named entities
Readable names such as amp, lt, gt, quot, copy, and reg are convenient for common symbols.
Numeric entities
Decimal and hexadecimal forms reference Unicode code points and are useful when no common named entity exists.
Validation
Malformed entity text remains visible, making it easier to spot input that needs manual cleanup.
Clear and reset
Clear the input field when you want to reset the preview and start a fresh conversion.
FAQ
What are HTML entities used for?
HTML entities represent reserved characters such as less-than, greater-than, ampersand, quotes, and symbols in a safe text form.
Does the encoder send my text to a server?
No. Encoding and decoding runs in your browser, so pasted text stays local to the page.
Should I use named or numeric entities?
Named entities are easier to read for common symbols. Numeric and hexadecimal entities work well for broader Unicode characters.
Can this prevent every XSS problem?
No. Entity encoding helps when rendering text in HTML, but security-sensitive apps should use framework escaping and context-aware sanitization.