HTML Encoder/Decoder

Encode or decode HTML entities and special characters. Convert ampersands, angle brackets, quotes, and apostrophes to their HTML entity equivalents and back.

Frequently Asked Questions

What is HTML encoding?
HTML encoding converts special characters into their HTML entity equivalents. For example, < becomes &lt; and & becomes &amp;. This prevents characters from being interpreted as HTML markup and helps prevent XSS attacks.
Why should I encode HTML?
HTML encoding is essential for security (preventing XSS attacks), displaying code examples on web pages, ensuring user-generated content renders safely, and meeting accessibility standards. Always encode dynamic content before inserting it into HTML.
What are common HTML entities?
The most common HTML entities are: &amp; (&), &lt; (<), &gt; (>), &quot; ("), &#39; ('), &#x27; ('), and &#x2F; (/). There are hundreds of named entities including &copy; (copyright), &reg; (registered), and &euro; (euro).
Is HTML encoding the same as URL encoding?
No. HTML encoding converts characters for safe display in HTML documents using &-based entities. URL encoding (percent-encoding) converts characters for safe transmission in URLs using %-encoded values. Different contexts require different encoding types.
Does HTML encoding prevent XSS attacks?
Yes, proper HTML encoding is one of the most effective defenses against Cross-Site Scripting (XSS) attacks. By encoding user input before inserting it into HTML, you prevent attackers from injecting malicious scripts.
What characters need to be HTML-encoded?
Five characters must always be encoded in HTML: & (ampersand), < (less than), > (greater than), double quote ("), and single quote ('). Other non-ASCII characters can optionally be encoded as named or numeric entities for broader compatibility.