What is HTML encoding?

HTML encoding (also called HTML entity encoding) replaces special characters that have meaning in HTML with their entity equivalents: becomes >, & becomes &, " becomes ". This prevents the browser from interpreting them as markup. Essential when displaying user-supplied content to prevent XSS attacks.

Why is HTML encoding important?

Without encoding, untrusted user input containing tags or HTML markup gets parsed and executed by browsers, creating XSS (cross-site scripting) vulnerabilities. Encoding turns active markup into displayable text. This is critical for comment systems, search results, form value redisplay, and any user input that gets echoed back to users.

What characters need to be encoded?

The 'big five': (greater-than), & (ampersand), " (double quote), ' (apostrophe). In HTML5, ' is also supported. Other characters are optional but sometimes encoded for safety: spaces ( ), em/en dashes, copyright/trademark symbols, etc. Most encoders only handle the big five by default.

What's the difference between named and numeric entities?

< (named) and < or < (numeric) all represent the < character. Named entities are more readable but limited to defined names; numeric entities work for any Unicode codepoint. Modern HTML5 supports both. Most encoders prefer named entities when available, numeric for unusual characters.

Should I encode HTML in JavaScript or PHP server-side?

Both. Defense in depth: encode at every output point where user content is displayed. Server-side prevents the bulk of attacks; client-side (template literals, frameworks like React) provides additional protection. React auto-escapes by default; this tool is for manual encoding scenarios.

What about URL encoding vs HTML encoding?

Different contexts. URL encoding (%26 for &) is for URLs; HTML encoding (& for &) is for HTML content. Mixing them creates double-encoding bugs. Use URL encoding when constructing URLs, HTML encoding when inserting into HTML. They're not interchangeable.

Will this tool encode all special characters?

By default, the 'big five' ( , &, ", '). Some encoders offer 'aggressive' or 'strict' modes that encode more (non-ASCII characters as numeric entities, control characters, etc.). For modern UTF-8 web pages, the big five are sufficient — encoding non-ASCII as entities is unnecessary if your page declares UTF-8.

Is the data sent to a server?

No. All encoding happens in your browser. Your text never leaves your device — safe for confidential content, email templates, or any HTML containing private information.

HTML Entity Encoder

Encode HTML entities online to safely display special characters in web pages. Free HTML entity encoder for angle brackets and quotes.

Encoding / Decoding Web & SEO

Instant results

Mode:

HTML Decode

Text to Encode

HTML Encoded Output

About HTML Encoding

HTML encoding converts special characters to HTML entities, preventing them from being interpreted as HTML code. This is essential for preventing XSS attacks and displaying special characters correctly in web pages.

Common Entities:

<: <

>: >

&: &

": "

How to Use HTML Entity Encoder

Paste your text or HTML

Paste content containing special HTML characters (<, >, &, ") into the input field. The encoded output appears instantly.

View encoded output

Special chars are replaced with HTML entities: < → <, > → >, & → &, " → ". Other characters pass through unchanged.

Use in HTML safely

The encoded output is safe to insert directly into HTML attributes, text content, or any context where raw HTML would be interpreted as markup. Prevents XSS.

Copy to use

Click Copy to put the encoded text on your clipboard. Use it in HTML templates, email content, comment systems, or any HTML output of user-supplied content.

When to Use HTML Entity Encoder

Preventing XSS in user-generated content

Comment systems, forum posts, search results — any place users can submit text that's later displayed back. HTML encoding the user input ensures their content displays as text, not executable markup. Without encoding, users can inject scripts that affect other visitors.

Constructing HTML attribute values

When building HTML strings programmatically with dynamic data, attribute values need encoding too. A user-supplied 'title' containing quotes or other special chars breaks the HTML structure. Encoding ensures attributes parse correctly: title="Hello "World"" instead of title="Hello "World"".

Email template generation

When generating HTML emails with personalized content (names, message text, custom messages), encode the dynamic parts to prevent template injection or HTML rendering issues. Most email frameworks auto-encode but manual encoding is sometimes needed for raw template manipulation.

Logging HTML responses

When logging HTML output for debugging or audit, encode the HTML so log readers (which often render HTML) display the raw content instead of interpreting it. Critical for security audit logs where understanding what was sent matters more than visual rendering.

HTML Entity Encoder Examples

Basic encoding

Input

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

Output

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

Dangerous script tags become safe text. Browsers display the encoded form as literal characters instead of executing the JavaScript. This is the textbook XSS prevention technique.

Email template

Input

Hello, John & Jane!

Output

Hello, John &amp; Jane!

The ampersand (&) is encoded as & to prevent it from being interpreted as the start of an entity. Without encoding, '& Jane' might be misparsed depending on what follows. Always encode & even when not strictly needed.

Attribute value

Input

<a title="Click \"here\" for more">link</a>

Output

&lt;a title=&quot;Click \&quot;here\&quot; for more&quot;&gt;link&lt;/a&gt;

When the entire HTML is encoded, all special chars including quotes are escaped. This produces text that can be safely displayed showing the literal HTML markup, not interpreted as actual elements.

Tips & Best Practices for HTML Entity Encoder

1.Always encode user-supplied content before HTML output. Even if you trust the user, encoding is cheap insurance against future input source changes.
2.Use server-side templating engines that auto-encode by default (Liquid, Jinja, ERB, Razor). Manual encoding is error-prone; framework defaults are safer.
3.Different output contexts need different encoding. HTML body uses HTML entities; URL query strings use URL encoding; JS string literals use JS encoding. Don't mix.
4.For HTML attributes specifically, also encode quotes (single and double) since they can break attribute parsing. Most encoders handle this automatically.
5.Don't double-encode. If your input is already encoded (e.g., from another system), encoding again creates &amp; instead of &. Track encoding state through your pipeline.
6.For modern frameworks (React, Vue, Svelte, Angular), text content is auto-encoded by default. You only need manual encoding when using dangerouslySetInnerHTML or similar bypass mechanisms.

Frequently Asked Questions

HTML encoding (also called HTML entity encoding) replaces special characters that have meaning in HTML with their entity equivalents: < becomes <, > becomes >, & becomes &, " becomes ". This prevents the browser from interpreting them as markup. Essential when displaying user-supplied content to prevent XSS attacks.

HTML Entity Encoder

About HTML Encoding

Common Entities:

How to Use HTML Entity Encoder

Paste your text or HTML

View encoded output

Use in HTML safely

Copy to use

When to Use HTML Entity Encoder

Preventing XSS in user-generated content

Constructing HTML attribute values

Email template generation

Logging HTML responses

HTML Entity Encoder Examples

Basic encoding

Email template

Attribute value

Tips & Best Practices for HTML Entity Encoder

Frequently Asked Questions

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