HTML Encode/Decode

Tool Introduction

This "HTML Encode/Decode" online tool is an efficient and practical web code conversion assistant. It can convert special characters in raw HTML code (such as <, >, &, ", etc.) and other characters that may cause parsing issues into their corresponding HTML entity encodings, ensuring they are displayed safely and correctly on web pages and preventing potential XSS attacks. At the same time, the tool also supports unescaping these HTML entity encodings back to the original HTML code. Whether you need to clean user input or want to display HTML code rather than parse it in specific scenarios, this tool provides a convenient solution.

The tool adopts a bidirectional conversion mode (converterType: "double"), enabling mutual conversion through two text boxes, "Before encoding" and "After encoding" (formFields). The core calculation logic is driven by the encode and decode functions (entryFunctions), making operation simple and intuitive.

How to Use

1. Open the tool page: Visit this "HTML Encode/Decode" online tool page.
2. Perform encoding operation:
     In the "Before encoding" text box, enter or paste the original HTML code or text you want to HTML entity encode. For example: <p>This is some<strong>HTML</strong> code</p>.
     The tool will automatically identify and convert it to HTML entity encoding, and the result will immediately appear in the "After encoding" text box.
3. Perform decoding operation:
     In the "After encoding" text box, enter or paste the encoded text you want to HTML entity decode. For example: <div>Hello &amp; World!</div>.
     The tool will automatically identify and convert it back to the original HTML code, and the result will immediately appear in the "Before encoding" text box.

Input parameter format and requirements:

• "Before encoding" text box (from): Accepts any plain text HTML code, fragments, or strings.
• "After encoding" text box (to): Accepts text that has been HTML entity encoded.

Output result format:

• When performing an encoding operation, the output result is text in HTML entity encoding format.
• When performing a decoding operation, the output result is the original HTML code text.

Usage Examples

This tool is based on a real-time conversion mechanism. The following examples demonstrate the correspondence between input and output.

• Scenario 1: Encode raw HTML code
    Operation demonstration: Paste the following content into the "Before encoding" text box.
    Example input data (Before encoding):
   

  <p>This is some<strong>HTML</strong> code & < > "</p>

  
    Expected output result (After encoding): (The tool will automatically display in the "After encoding" text box)
   

  <p>This is some<strong>HTML</strong> code & < > "</p>

• Scenario 2: Decode HTML entity encoded text
    Operation demonstration: Paste the following content into the "After encoding" text box.
    Example input data (After encoding):
   

  <div>Hello & World! 你好</div>

  
    Expected output result (Before encoding): (The tool will automatically display in the "Before encoding" text box)
   

  <div>Hello & World! 你好</div>

Frequently Asked Questions

• Q: What are the main scenarios for HTML encoding? A: HTML encoding is mainly used to safely display special characters on web pages, prevent XSS (Cross-Site Scripting) attacks, and avoid character conflicts and rendering errors during HTML document or data transmission. For example, when you want to display HTML code itself instead of having the browser parse it, encoding is required.
• Q: What input formats does this tool support? A: This tool supports any plain text HTML code, HTML fragments, or text that has been HTML entity encoded. No specific file format is required; just copy and paste.
• Q: What is the format of the output result? A: If you perform an encoding operation, the output result is text in HTML entity encoding format that conforms to HTML specifications; if you perform a decoding operation, the output result is the original HTML code text.
• Q: What is the difference between HTML encoding and URL encoding? A: HTML encoding is for escaping special characters in HTML documents to ensure they are correctly parsed and displayed by the browser, mainly involving <, >, &, ", etc. URL encoding (or percent-encoding) is for escaping special characters in URLs to ensure the URL's validity and correct transmission, mainly involving spaces, #, /, ?, etc. Their goals and the character sets they escape are different.
• Q: Does it support character encoding for all languages? A: Yes, this tool typically converts multi-byte characters (such as Chinese, Japanese, Korean, etc.) into their corresponding numeric HTML entity encodings (e.g., &#xXXXX; or &#NNNN;), ensuring correct display in any character set environment.

Notes

• Input data format requirements: Please ensure that the content entered into the text box is plain text. Avoid directly pasting content that includes non-text elements such as images or files, as this may lead to conversion failure or abnormal results.
• Character set compatibility: Although HTML entity encoding has good compatibility, in actual web development, it is still recommended to unify the HTML document's character set declaration (e.g., <meta charset="UTF-8">) for optimal display.
• Conversion completeness: The tool will comprehensively encode or decode common HTML special characters as much as possible. However, some extreme or custom entities may not be within the default processing scope.
• Security tip: While HTML encoding helps prevent XSS attacks, it is not the only security measure. When processing user input, other backend validation and filtering mechanisms should still be combined to build a multi-layered security defense system.