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HTML Encoder/Decoder

Encode and decode HTML entities for web development

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Quick Examples

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Understanding HTML Entities

HTML entities are special character sequences that begin with an ampersand (&) and end with a semicolon (;). They serve two main purposes: representing reserved HTML characters and displaying special symbols.

Essential HTML Entities

&lt;<
&gt;>
&amp;&
&quot;"
&apos;\'

Common Special Characters

&copy;©
&reg;®
&trade;
&euro;
&nbsp;(non-breaking space)

XSS Prevention with HTML Encoding

Cross-Site Scripting (XSS) is one of the most common web vulnerabilities. Proper HTML encoding is a critical defense mechanism.

Dangerous (Unencoded)

<div>{user_input}</div>

Safe (Encoded)

<div>{encoded_user_input}</div>

Best Practices

  1. 1.
    Always encode user input: Never trust user-provided data. Encode it before displaying in HTML contexts.
  2. 2.
    Use context-appropriate encoding: HTML encoding is for HTML content. Use different encoding for JavaScript, URLs, or CSS contexts.
  3. 3.
    Encode at output, not input: Store data in its original form and encode when rendering to preserve data integrity.
  4. 4.
    Use minimal encoding for readability: Only encode what's necessary unless you have specific requirements for aggressive encoding.
  5. 5.
    Validate decoded content: When decoding entities, check for malicious patterns before using the content.

Frequently Asked Questions

Common questions about the HTML Encoder/Decoder

HTML entities are special character sequences that represent reserved characters in HTML. Characters like <, >, &, and quotes must be encoded when you want to display them as text rather than HTML markup. Encoding prevents browsers from interpreting these characters as HTML code and helps prevent XSS attacks.

ℹ️ Disclaimer

This tool is provided for informational and educational purposes only. All processing happens entirely in your browser - no data is sent to or stored on our servers. While we strive for accuracy, we make no warranties about the completeness or reliability of results. Use at your own discretion.