HTML entity encoding is a method to represent special characters as &#number; or &name; sequences. It was originally designed to allow characters that are difficult to input directly in HTML (such as angle brackets, quotation marks, copyright symbols, etc.) to be displayed correctly. For example, < is encoded as <, > as >, and & itself as &. This encoding is widely used in web development, content management systems, and email templates.
Named entities use predefined names (e.g., <, >, &), which are easy to remember but limited in number—HTML5 defines approximately 252 named entities. Numeric entities use Unicode code points (e.g., <), can represent all Unicode characters (over 140,000), but are less readable. Decimal numeric entities use the &#number; format, while hexadecimal uses &#xnumber;. In practice, named entities are commonly used for basic special characters, while numeric entities are used for Unicode extended characters and Emoji.
• < → < (less than) > → > (greater than) & → & (ampersand)
• " → " (double quote) ' → ' (single quote) → non-breaking space
• © → © (copyright) ® → ® (registered) ™ → ™ (trademark)
• — → — (em dash) … → … (ellipsis) ☕ → ☕ (Emoji)
• Code display: Encode tag symbols when showing HTML/CSS/JavaScript code examples on web pages
• XSS prevention: Encoding user input is a fundamental technique to prevent cross-site scripting attacks
• URL parameters: Encode text containing special characters when passing them in URL parameters
• Email templates: Email clients have strict HTML parsing requirements; encoding prevents display issues
• International content: Handle special characters from different languages (Arabic, Thai, etc.)
This HTML entity encoder and decoder is easy to use with comprehensive features. Here is a detailed guide:
Encoding: Paste the text you want to encode into the left input box (can be any Unicode characters including Chinese, Emoji, special symbols, etc.), select an encoding mode, and click the "Encode" button. The tool supports three encoding modes: named entities (e.g., <), decimal numeric entities (e.g., <), and hexadecimal numeric entities (e.g., <). Check "Encode all characters" to convert every character (including letters and numbers) to entity encoding; otherwise, only HTML special characters (< > & " ') will be encoded.
Decoding: Paste an HTML entity-encoded string into the input box and click the "Decode" button to restore the original text. The tool automatically recognizes mixed inputs of named, decimal, and hexadecimal entities without requiring manual format selection. It supports batch decoding of long texts and can handle incomplete entity encodings (such as entities missing semicolons).
Shortcuts: Click "Swap" to move the result text to the input area for chained operations (e.g., encode then decode to verify). Click "Copy" to copy the result to the clipboard with one click. Supports Ctrl+Enter shortcut for quick encoding.
HTML entity encoding has a wide range of applications in web development and content processing. Here are several typical use cases:
Technical Blogs and Tutorials: When displaying HTML code examples in blog posts or documentation, you must encode special characters like angle brackets and quotes so browsers display them as plain text rather than parsing them as tags. This tool helps you quickly encode code snippets for pasting into editors.
Web Security: Encoding user input before rendering it on a web page is a fundamental defense against XSS (cross-site scripting) attacks. By encoding <script> as <script>, even if a malicious user inputs script tags, the browser will display them as plain text instead of executing them. This tool helps security developers quickly test encoding effects.
Email Template Development: Email clients (such as Outlook, Gmail, etc.) parse HTML more strictly than regular browsers. Many special characters can cause email content display issues if not entity-encoded. Using this tool to preprocess special characters in email templates can effectively prevent garbled text or formatting errors.
Unicode and HTML Entities: HTML entity encoding is essentially a representation of Unicode code points. Named entities are aliases for Unicode code points (e.g., < corresponds to U+003C), while numeric entities directly use code point values (e.g., < corresponds to U+003C). This means HTML entities can represent all Unicode characters, including Chinese (e.g., 中 for 中), Emoji (e.g., ☕ for ☕), and special letters from various languages.
HTML Entity Encoding vs URL Encoding: HTML entity encoding and URL encoding (percent-encoding) are two different encoding mechanisms. HTML entities are used to represent special characters within HTML documents in the &#number; or &name; format. URL encoding is used to represent special characters within URLs in the %XX format. The encoding tables and purposes are completely different and not interchangeable.
Related Tools: If you need to handle URL encoding, try our "URL Encoder/Decoder" tool. If you need to convert text to Base64, use our "Base64 Encoder/Decoder" tool. Additionally, our "HTML Formatter" can help you beautify and validate HTML code, and our "JSON Formatter" is suitable for processing API data.
HTML entity encoding is a method to represent special characters as &#number; or &name; sequences. For example, < is represented as <, > as >, and & as &. This prevents characters from being misinterpreted by HTML parsers, ensuring content displays correctly.
Decimal entities use the &#number; format (e.g., <), while hexadecimal entities use the &#xnumber; format (e.g., <). Both represent the same character; decimal is more intuitive, while hexadecimal is more common among developers.
Yes. This tool supports all Unicode characters, including Chinese, Emoji, rare characters, and more. Non-ASCII characters are converted to their corresponding Unicode code points, e.g., U+4E2D becomes 中 (decimal) or 中 (hexadecimal).
You need HTML entity encoding when displaying raw HTML tags in tutorials, sanitizing user input to prevent XSS attacks, passing special characters in URL parameters, or handling special characters in email templates.
Named entities use predefined names (e.g., <, >, &), which are easy to remember but limited in number. Numeric entities use Unicode code points (e.g., <), can represent any character, but are less readable.
No. All encoding and decoding operations are performed locally in your browser. Your data never leaves your device, ensuring complete privacy and security.