HTML Entity Encoder

What Is a HTML Entity Encoder?

HTML entity encoding is a critical security practice and a daily development task. Properly encoding user-generated content before rendering it in HTML prevents XSS vulnerabilities — one of the OWASP Top 10 web application security risks. Beyond security, HTML encoding is needed for displaying special characters like mathematical symbols, currency signs, and non-ASCII characters in web pages.

Example

Text Input:

<script>alert("XSS")</script> & "quotes"

HTML Entities Output:

&lt;script&gt;alert(&quot;XSS&quot;)&lt;/script&gt; &amp; &quot;quotes&quot;

How to Use This Converter

Paste your Text data into the input panel.
View the converted HTML Entities output — it updates instantly.
Click Copy to copy the result to your clipboard.
Verify the output matches your expectations before using in production.

Developer Tips

The five mandatory HTML entities are ampersand, less-than, greater-than, double-quote, and single-quote. Failing to encode these in user-generated content is the primary vector for cross-site scripting attacks.
URL encoding (percent-encoding) and HTML encoding are different systems. A space is %20 in URLs but a numeric entity in HTML. Using the wrong encoding in the wrong context causes double-encoding bugs.
Modern frameworks (React, Vue, Angular) auto-encode output by default, but raw HTML injection bypasses this protection. If you are using escape hatches, encode manually first.

Related Converters

All conversions run entirely in your browser — no data is sent to any server. For the specification, see WHATWG — Named Character References.

Frequently Asked Questions

What is HTML encoding?

HTML encoding replaces characters that have special meaning in HTML (<, >, &, ", ') with their entity equivalents (<, >, &, ", '). This prevents browsers from interpreting those characters as HTML tags or attributes.

Why is HTML encoding important for security?

HTML encoding prevents Cross-Site Scripting (XSS) attacks. If user input containing <script> tags is displayed without encoding, the browser executes the script. Encoding converts < to <, making it display as text instead of executing as code.

What characters need HTML encoding?

At minimum: < (<), > (>), & (&), " ("), and ' ('). In HTML attribute contexts, additional characters may need encoding. When in doubt, encode everything except alphanumeric characters.

Is HTML encoding the same as URL encoding?

No — they serve different purposes and use different syntax. HTML encoding uses named or numeric entities (&, <) for displaying characters safely in HTML. URL encoding uses percent-encoding (%26, %3C) for including characters safely in URLs.

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