HTML Entity Encoder

Developer

Encode special characters to HTML entities or decode them. Essential for XSS prevention and web development.

What is This Tool?

An HTML entity encoder/decoder converts special characters to and from their HTML entity representations. Encode characters like <, >, &, and " to prevent XSS vulnerabilities and rendering issues, or decode entities back to their original characters for debugging.

HTML entities come in three forms: named (& < >), decimal (&), and hexadecimal (&). Proper entity encoding is critical for security (preventing XSS attacks) and correctness (displaying reserved HTML characters as text rather than markup).

Common Use Cases

XSS Prevention

Encode user-generated content before rendering in HTML to prevent cross-site scripting attacks.

HTML Debugging

Decode HTML entities in source code, API responses, and database records to see the original characters.

Email Templates

Encode special characters in HTML emails to ensure correct rendering across different email clients.

Content Migration

Clean up double-encoded entities and convert between named and numeric entity formats during CMS migrations.

Frequently Asked Questions

Which characters must be encoded?

At minimum: < (<), > (>), & (&), " ("), and ' ('). These characters have special meaning in HTML and can break rendering or enable XSS.

What is the difference between named and numeric entities?

Named entities use mnemonics (&). Numeric use code points (& or &). Numeric entities support all Unicode characters; named entities are limited to a defined set.

Should I encode all non-ASCII characters?

Not if your page declares UTF-8 encoding (which it should). Non-ASCII characters render correctly in UTF-8 without entity encoding.