What is an HTML Entity Decoder & Encoder?
An HTML Entity Decoder & Encoder is a web development and cyber security utility designed to translate reserved HTML markup characters into escaped HTML entities and vice versa. In HTML syntax, characters like less-than (<), greater-than (>), and ampersands (&) are reserved for tag parsing. To display these characters safely as literal text without triggering syntax errors or Cross-Site Scripting (XSS) vulnerabilities, browsers utilize character entity references.
HTML Entity Formats: Named vs Decimal vs Hexadecimal
HTML entities can be formatted in three standard representations:
- Named Entities: Human-readable aliases prefixed with an ampersand and ending with a semicolon (e.g.,
<for <,©for ©,€for €). - Decimal Numeric Entities: Unicode decimal code point prefixed with
&#(e.g.,<for <,©for ©). - Hexadecimal Entities: Hexadecimal Unicode code point prefixed with
&#x(e.g.,<for <,©for ©).
Common HTML Entities Reference Table
| Character | Named Entity | Decimal Code | Hex Code | Security / Usage Purpose |
|---|---|---|---|---|
| & | & | & | & | Mandatory escape in URLs and text nodes |
| < | < | < | < | Prevents browser from parsing opening HTML tags |
| > | > | > | > | Prevents closing HTML tag injection |
| " | " | " | " | Escapes HTML attribute quotes |
| ' | ' | ' | ' | Escapes single-quoted JavaScript and attributes |
| © | © | © | © | Copyright notice in website footers |
Frequently Asked Questions
Why is HTML encoding critical for web security?
Unsanitized user input containing characters like <script> or "> can execute malicious scripts in visitors' browsers (Stored or Reflected Cross-Site Scripting / XSS). Escaping these characters into HTML entities renders them as harmless text strings.
Can this tool decode deeply nested entities?
Yes. If your text contains double-encoded entities (such as &lt;), you can click Swap and process multiple times to decode down to raw plain text.
Does this tool work client-side?
Yes! 100% of the decoding and encoding runs locally inside your browser via standard JavaScript DOM APIs, ensuring private code or sensitive API tokens are never transmitted to external servers.
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