What characters does HTML encoding convert?

The five critical characters are: & → &, → >, " → ", and ' → '. These are the characters browsers parse as HTML syntax.

What is the difference between HTML encoding and URL encoding?

HTML encoding converts characters to HTML entity references and is used within HTML content. URL encoding converts characters to %XX hexadecimal sequences for use within URLs. They are different mechanisms for different contexts.

Why should I encode user input before displaying it?

If you display user input without encoding, malicious users could submit JavaScript code that executes in visitors' browsers — a Cross-Site Scripting (XSS) attack. Always encode untrusted content before rendering in HTML.

Does HTML encoding affect the visual appearance of text?

No. Browsers automatically decode HTML entities when rendering, so visitors see the original characters. The encoding only affects the raw HTML source code.

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🏷️ HTML Encoder / Decoder

Convert special characters to HTML entities and back.

Output

What is an HTML Encoder / Decoder?

An HTML encoder converts special characters that have meaning in HTML syntax into their safe entity equivalents. For example, the less-than sign < becomes <, the ampersand & becomes &, and double quotes become ". This prevents browsers from interpreting content as HTML tags — a critical step for preventing Cross-Site Scripting (XSS) vulnerabilities in web applications.

HTML decoding does the reverse: it converts entity references back into their original characters. This is useful when you receive HTML-encoded data from an API, database, or CMS and need to display or process the raw text. Web developers, content managers, and cybersecurity professionals use HTML encoding daily to safely handle user-generated content and prevent injection attacks.

How to Use the HTML Encoder / Decoder

Paste your text or HTML into the input box.
点击 Encode HTML to convert special characters (< > & " ') to entities.
点击 Decode HTML to convert entity references back to their original characters.
使用 Swap to move the output to the input, then click Copy to copy the result.

Why Use Our HTML Encoder / Decoder?

100% 免费 — No cost, no usage caps.
无需注册 — Instant access without an account.
基于浏览器 — Text never leaves your browser; processed using native DOM APIs.
XSS Prevention — Correctly encodes the five critical HTML characters that enable script injection.
Bidirectional — Both encode and decode in one tool with swap functionality.

常见问题解答

The five critical characters are: & (ampersand) → &, < (less-than) → <, > (greater-than) → >, " (double quote) → ", and ' (single quote) → '. These are the characters browsers parse as HTML syntax, so encoding them prevents XSS attacks.

HTML encoding converts characters to HTML entity references (<, &) and is used within HTML content and attributes. URL encoding (percent-encoding) converts characters to %XX hexadecimal sequences and is used within URLs. They are different escape mechanisms for different contexts.

If you display user input without encoding it, a malicious user could submit JavaScript code as their input (e.g. <script>alert('XSS')</script>), which would execute in every visitor's browser. This is called a Cross-Site Scripting (XSS) attack. Always encode untrusted content before rendering it in HTML.

No. Browsers automatically decode HTML entities when rendering a page, so visitors see the original characters. The encoding only affects the raw HTML source code. & in source renders as & in the browser, < renders as <, and so on.

要闻速览

✓ 100% 免费，无隐藏费用
✓ 无需帐户或登录
✓ 适用于任何浏览器
✓ 您的数据永远不会离开您的设备
✓ Prevents XSS — encodes all 5 critical HTML characters