HTML Entity Encoder & Decoder — Free Online

Encode and decode HTML entities instantly with this free online tool. Escape special characters to prevent XSS and display issues. No sign-up required.

What are HTML Entities?

HTML entities are special sequences used to represent reserved characters in HTML. Characters like the less-than sign, greater-than sign, ampersand, and double quote have special meaning in HTML syntax — for example, the less-than sign opens a tag and the ampersand starts a character reference. If you want to display these characters as literal text on a web page, you must replace them with their entity equivalents (e.g. the 'lt' entity for less-than, 'gt' for greater-than, 'amp' for ampersand, and 'quot' for double quotes). Failing to encode these characters can break page rendering or, worse, create Cross-Site Scripting (XSS) vulnerabilities when user input is rendered as HTML. Entity encoding is also used for characters not available on the keyboard, such as the copyright symbol (©), euro sign (€), and em dash (—).

How to Use This Free Online HTML Entity Encoder & Decoder

  1. Select the mode: 'Encode' to convert special characters to HTML entities, or 'Decode' to convert entities back to readable characters.
  2. Paste or type your HTML content into the input field.
  3. The converted result appears instantly in the output field — no button click needed.
  4. Click the Copy button to copy the result to your clipboard.

Common Use Cases for HTML Entity Encoding

  • Preventing XSS attacks — Encode user-supplied input before rendering it in HTML to neutralize script injection attempts and prevent Cross-Site Scripting vulnerabilities.
  • Displaying code snippets on web pages — When showing HTML source code in a tutorial or documentation page, encode the tags so the browser renders them as text instead of interpreting them.
  • Embedding special characters in HTML attributes — Characters like double quotes and ampersands inside attribute values must be encoded to avoid breaking the attribute syntax.
  • Debugging encoded HTML content — Decode HTML entities to inspect the original characters when troubleshooting rendering issues or reviewing sanitized output from a CMS.

FAQ

What is the difference between HTML encoding and URL encoding?
HTML encoding (entity encoding) converts characters like the less-than sign and ampersand into HTML-safe entity sequences for safe display in web pages. URL encoding (percent encoding) converts characters into %XX format for safe use in URLs. They serve different purposes and are not interchangeable.
Does HTML encoding prevent XSS?
HTML entity encoding is one of the most important defenses against XSS when applied correctly. Encoding output that is inserted into HTML body content neutralizes injected script tags. However, a complete XSS prevention strategy also includes Content Security Policy headers and context-aware encoding for attributes, JavaScript, and CSS contexts.
Which characters must be encoded in HTML?
At minimum, you must encode the five characters that have special meaning in HTML: the ampersand, less-than sign, greater-than sign, double quote, and single quote. For defense-in-depth, many libraries also encode /, backtick, and =
Is this tool free and private?
Yes. All encoding and decoding happens in your browser using JavaScript. No data is transmitted to any server and no account is needed.

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