UD5 Toolkit
String to Escaped HTML - Online Protect Against XSS
Copied to clipboard!
String to Escaped HTML
Protect against Cross-Site Scripting (XSS) by converting special characters into safe HTML entities. Essential for web developers handling user-generated content.
Input String
0 chars
Escaped HTML
0 chars
Detected:
Safe — No dangerous characters
Safe Render Preview
(how it displays in browser)
Preview will appear here...
Input: 0 chars
Output: 0 chars
Frequently Asked Questions
HTML escaping converts special characters like
<, >, &, ", and ' into their corresponding HTML entities (e.g., <, >). This prevents browsers from interpreting user input as executable HTML or JavaScript, which is the primary defense against Cross-Site Scripting (XSS) attacks. Without escaping, an attacker could inject malicious scripts that steal user data, hijack sessions, or deface websites.
The five critical characters are: & (ampersand →
&), < (less-than → <), > (greater-than → >), " (double quote → "), and ' (single quote → '). In attribute contexts, quotes are especially dangerous. For comprehensive protection, also consider escaping / (forward slash → /) to prevent breaking out of HTML comments or closing tags prematurely.
XSS attacks rely on injecting executable code (like
<script>alert('xss')</script>) into web pages. When this input is properly escaped to <script>alert('xss')</script>, the browser treats it as plain text rather than executable HTML. The escaped string displays literally on the page but does not execute. This simple transformation neutralizes the vast majority of reflected and stored XSS attack vectors.
Basic HTML escapes only the 5 most critical characters (
&, <, >, ", '), which covers the majority of XSS attack surfaces. Full Entities goes further by escaping all non-ASCII and special characters (like /, `, =, parentheses, etc.) into their entity equivalents. Full mode is recommended when you need maximum security, such as when handling completely untrusted user input in sensitive contexts like HTML attributes or legacy systems.
Both formats are interchangeable in modern browsers. Hexadecimal entities (
<) are more compact for higher Unicode codepoints and are preferred by many developers for readability when dealing with hex values. Decimal entities (<) are sometimes preferred in XML contexts or when working with systems that expect decimal notation. For everyday HTML escaping, either works perfectly—choose based on your team's coding standards or the conventions of your codebase.
HTML escaping is the first and most important line of defense, but it is not a silver bullet. XSS can also occur in JavaScript contexts (use
JSON.stringify() or proper JS escaping), CSS contexts, URL parameters (use URL encoding), and HTML attribute contexts without quotes. A robust security strategy combines escaping with Content Security Policy (CSP) headers, input validation, sanitization libraries like DOMPurify, and secure coding practices like avoiding innerHTML in favor of textContent.
The safest built-in method is to use the browser's DOM API: create a text node with
document.createTextNode(str) or set element.textContent = str. For string-based escaping, a reliable function maps characters to entities: str.replace(/[&<>"']/g, char => entityMap[char]). Avoid using innerHTML with untrusted content. Libraries like DOMPurify provide additional sanitization. This tool's JavaScript implementation can be inspected in your browser's developer console for a production-ready escaping function.
Yes! This tool handles multi-line text and large inputs efficiently. You can paste entire HTML fragments, JSON strings containing special characters, or code snippets. The real-time conversion processes your input instantly. For programmatic bulk processing, the underlying escaping logic can be replicated server-side in any language (PHP's
htmlspecialchars(), Python's html.escape(), Java's StringEscapeUtils, etc.). Bookmark this page for quick access when you need to escape strings during development.