Automarkly logo
    Developer

    HTML Encoder & Decoder

    Encode special characters into HTML entities or decode HTML entities back into plain text. Protect web apps from XSS.

    Ad space — Top Tool Banner — 728x90 / responsive
    Ad space — Below Tool — Responsive Banner

    About HTML Encoder & Decoder

    When embedding code snippets or user-submitted input inside HTML pages, special characters like `<`, `>`, `&`, and `"` can break markup or create dangerous Cross-Site Scripting (XSS) vulnerabilities. XSS is one of the most common web security flaws, consistently appearing in the OWASP Top 10. A single unencoded `<script>` tag in user input can compromise an entire application.

    Automarkly HTML Encoder & Decoder transforms special characters into safe HTML entities (e.g. `<` becomes `&#60;`) or reverses encoded entity strings back into clean plain text. This bidirectional tool is essential for web developers, technical bloggers, and security engineers who need to display code examples safely or sanitize user-generated content before rendering.

    The tool handles all reserved HTML characters including `<`, `>`, `&`, `"`, `'`, and non-ASCII Unicode characters. It uses both numeric entity references (like `&#60;`) and named entities (like `<`) to ensure maximum compatibility across browsers and rendering contexts. The DOMParser API powers the decode function, accurately reversing any valid HTML entity back to its original character.

    For security teams, HTML encoding is a critical defense-in-depth measure. The OWASP-recommended approach is to encode on output — store raw data in your database and encode it when rendering to HTML. This ensures data flexibility and context-appropriate protection. Our tool makes this workflow effortless: paste user input, click encode, and paste the safe output into your template.

    Technical writers and bloggers frequently need to display HTML code examples in their articles. Without encoding, a code snippet like `<div class="hero">` would be interpreted as actual HTML by the browser, disappearing from the rendered page. Encoding converts it to `&lt;div class="hero"&gt;` so it displays correctly as readable code. Our tool handles this conversion in one click.

    Everything runs entirely in your browser memory for maximum speed and security. Your code snippets, configuration files, and sensitive data never leave your device. The tool is free with no registration, no limits, and no watermarks. Use it as often as you need for personal projects, commercial applications, or enterprise security audits.

    How to Use HTML Encoder & Decoder

    1

    Type or paste your HTML code snippet or encoded entity string.

    2

    Click 'Encode HTML' to convert special symbols into entity references.

    3

    Click 'Decode HTML' to restore encoded entities back into plain text.

    4

    Copy your encoded or decoded output with one click.

    Key Benefits

    Security Protection: Prevent XSS vulnerabilities and HTML injection bugs.
    Instant Encoding: Convert special characters to numeric and named HTML entities.
    Bidirectional Tool: Easily toggle between encoding and decoding.
    100% Client-Side: Your code snippets stay completely private in browser memory.
    Free Developer Utility: Unlimited usage with zero registration required.

    Common Use Cases

    Encoding a code snippet containing <script> tags for display in a blog post: <script>alert('xss')</script> becomes &lt;script&gt;alert(&#39;xss&#39;)&lt;/script&gt; — renders as text, not executable code.
    Encoding user input before displaying in HTML: a comment containing <img onerror='steal()'> becomes &lt;img onerror=&#39;steal()&#39;&gt; — prevents XSS execution.
    Decoding HTML entities in scraped content: &lt;p&gt;Hello&lt;/p&gt; decodes to <p>Hello</p> — useful for processing scraped HTML data.
    Encoding email addresses to prevent email harvesting bots: john@example.com becomes john&#64;example&#46;com — bots can't easily parse the encoded address.
    Encoding special characters in XML content: Tom & Jerry becomes Tom &amp; Jerry — prevents XML parsing errors from unescaped ampersands.

    Frequently Asked Questions

    Why should I encode HTML entities?

    Encoding converts reserved HTML characters into safe entity codes so browsers display them as text instead of executing them as HTML code.

    Which characters are encoded?

    Special characters including `<`, `>`, `&`, `"`, `'`, and non-ASCII Unicode characters are converted to entity format.

    Is my code sent to a server?

    No, all entity encoding and decoding is calculated inside your web browser.

    Tips & Best Practices

    Use numeric entities (&#60;) for maximum browser compatibility, or named entities (<) for readability.
    Don't rely on encoding alone for XSS protection — combine with Content Security Policy (CSP) headers.
    When displaying code snippets in blog posts, encode the entire snippet to prevent the browser from interpreting tags.
    Test encoded output in multiple browsers to ensure consistent rendering of special characters.
    For attribute values, encode quotes (" and ') in addition to <, >, and & to prevent attribute injection.

    Conclusion

    The HTML Encoder & Decoder is an essential tool for web developers and security engineers, making it effortless to safely display code snippets and protect against XSS vulnerabilities. By encoding special characters into HTML entities, you ensure user-generated content renders as text rather than executing as markup. Use this tool alongside CSP headers and input validation for defense-in-depth. Explore our related developer and security tools for more resources.

    Related Tools

    Related Articles