HTML Encoder/Decoder

How it works

1. Enter HTML code. 2. Choose Encode or Decode. 3. Click Convert.

When to use it

The HTML encoder is essential for:

• XSS prevention: encode user input before inserting in HTML pages to prevent Cross-Site Scripting attacks.
• Technical documentation: show HTML code as text in web pages without it being interpreted by the browser.
• CMS and blogs: insert code snippets in articles without them being executed.
• HTML email: handle special characters in HTML emails to ensure correct display.
• Template engines: prepare data for templates that require pre-encoded HTML entities.

Advantages

Protects against XSS. Converts all special characters. Ideal for developers.

Benefits vs alternatives

Advantages over manual encoding:

• Complete: encodes all critical characters: < > & " ' and Unicode characters.
• Secure: prevents XSS vulnerabilities by eliminating the risk of HTML injection.
• Reversible: decode to return to original text when needed.
• Privacy: browser-side processing, no data transmitted.

Common mistakes to avoid

1. Not encoding user input: inserting unencoded user input in HTML opens the door to XSS vulnerabilities. Always encode user-provided data.
2. Over-encoding: encoding already-encoded HTML turns "&amp;" into "&amp;amp;". Check if text is already encoded.
3. Encoding intentional tags: if you want to insert valid HTML (e.g. a link), don't encode it. Only encode text that should be displayed literally.
4. Forgetting attributes: HTML attribute values must also be encoded to prevent injection.

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