🛡️ XSS Vulnerability Tester

Test your website for cross-site scripting vulnerabilities and security issues

Version 2.1.0 - Updated September 2025

Target URL

XSS Payloads (one per line)

Test Type

Reflected XSS

Stored XSS

DOM-based XSS

Blind XSS

Payload Type

Basic

Advanced

Obfuscated

Custom

Test Parameters (comma separated)

Security Level: Not Tested

Test results will appear here

Embed This Tool

Want to embed this XSS tester on your website? Use this code:

🎯 XSS Examples & Attack Vectors

✅ Basic Reflected XSS

Simple script injection through URL parameters:

https://vulnerable-site.com/search?q=<script>alert('XSS')</script>

Impact: Script executes when page loads with the malicious parameter

🖼️ Image-based XSS

Using image tags with onerror events:

Impact: Executes when image fails to load, bypassing some filters

🔗 DOM-based XSS

Manipulating DOM elements directly:

https://vulnerable-site.com#<img src=x onerror=alert('XSS')>

Impact: Client-side script execution without server reflection

📝 Stored XSS

Persistent attack stored in database:

Comment: Great post! <script>stealCookies()</script>

Impact: Affects all users viewing the compromised content

🌀 Obfuscated XSS

Encoding payloads to bypass filters:

<script>eval(String.fromCharCode(97,108,101,114,116,40,39,88,83,83,39,41))</script>

Impact: Bypasses basic input validation and WAF rules

🎯 Advanced Vector

Combining multiple techniques:

javascript:/*-->*/<img src=x onerror=alert('XSS')>

Impact: Multi-layered attack that bypasses multiple defenses

📚 XSS Security Tutorials

🛡️

Understanding XSS Vulnerabilities

Learn the fundamentals of cross-site scripting attacks and how they can compromise web applications.

Read Tutorial →

🔍

XSS Testing Methodology

Comprehensive guide to testing web applications for XSS vulnerabilities using systematic approaches.

Read Tutorial →

⚡

Advanced XSS Prevention

Implementing robust security measures to protect against sophisticated XSS attacks.

Read Tutorial →

🚫

Common XSS Defense Mistakes

Learn about frequent security implementation errors and how to avoid them.

Read Tutorial →

📊

XSS in Modern Web Frameworks

How modern frameworks like React, Angular, and Vue handle XSS and where vulnerabilities still exist.

Read Tutorial →

🌐

Real-world XSS Case Studies

Analysis of notable XSS attacks in the wild and lessons learned from security breaches.

Read Tutorial →

⚖️ XSS Testing Tools Comparison

Compare our free XSS tester with other popular security testing tools and services:

Feature	Our Tool	Online Tool A	Security Suite B	Browser Extension
Free to Use	✅	✅	❌ (Premium)	✅
Custom Payloads	✅	✅ (Limited)	✅	❌
Multiple XSS Types	✅ (All types)	✅ (Basic only)	✅	✅
Real-time Results	✅	✅	✅	✅
Security Level Assessment	✅	❌	✅	❌
Client-Side Testing	✅ (Secure)	❌ (Server-side)	❌ (Server-side)	✅
Mobile Friendly	✅	✅	✅	✅
Educational Content	✅	❌	✅	❌
Privacy (No data sent)	✅	❌	❌	✅

Why Choose Our XSS Tester?

🔒 Complete Privacy

All testing happens in your browser. Your URLs and test data never leave your device, ensuring maximum privacy and security.

🎛️ Full Customization

Control every aspect of your XSS testing - payloads, test types, parameters, and security assessment levels.

📊 Comprehensive Assessment

Get detailed security level assessment with visual indicators and actionable recommendations.

🎓 Educational

Not just a tool - includes comprehensive guides, examples, and best practices for web security.

📝 Version History & Changelog

Version 2.1.0 - Latest

September 15, 2025

🎉 Added security level assessment with visual indicators
📊 Enhanced test statistics and performance metrics
📱 Improved mobile responsiveness and touch interactions
🔧 Added embed code functionality for easy integration
📚 Expanded educational content and attack examples
🎨 Updated UI with better accessibility and contrast

Version 2.0.0

August 20, 2025

🔄 Complete UI redesign with modern styling
📚 Added comprehensive tutorial section
📝 Introduced tabbed navigation for better organization
⚖️ Added tool comparison feature
💾 Implemented detailed report generation
📋 Enhanced copy functionality with better feedback

Version 1.2.0

July 10, 2025

✅ Added multiple XSS test types (Reflected, Stored, DOM, Blind)
🛡️ Improved payload library with advanced attack vectors
📖 Added real-world attack examples and case studies
🐛 Fixed URL parsing issues on mobile devices
♿ Enhanced accessibility with ARIA labels

Version 1.1.0

June 5, 2025

🎨 Improved visual design with gradient backgrounds
📱 Added responsive design for mobile devices
⚠️ Added warnings for potentially dangerous payloads
📋 Implemented one-click copy functionality
🔧 Fixed payload encoding issues

Version 1.0.0

May 15, 2025

🎉 Initial release of XSS Vulnerability Tester
🔐 Support for basic reflected XSS testing
⚡ Client-side processing for maximum privacy
📚 Comprehensive documentation and examples
✨ Clean, modern user interface

🔮 Upcoming Features

📋 Planned for Next Release:

Automated website crawling for comprehensive testing
CSRF vulnerability testing integration
Advanced obfuscation techniques for payloads
Browser extension for in-page testing
Dark/Light theme toggle
API for programmatic testing
Integration with popular security frameworks

What is XSS (Cross-Site Scripting)?

Cross-Site Scripting (XSS) is a security vulnerability that allows attackers to inject malicious scripts into web pages viewed by other users. These attacks occur when a web application uses unvalidated or unencoded user input in its output.

🟢 Types of XSS Attacks

✅ Common XSS Variants:

Reflected XSS: Malicious script comes from the current HTTP request
Stored XSS: Malicious script is stored on the server and served to users
DOM-based XSS: Vulnerability exists in client-side code rather than server-side code
Blind XSS: Attack payload is stored and executed in a different application/context

🔴 Common XSS Attack Vectors

❌ Vulnerable Input Points:

Search fields and query parameters
Form inputs (comments, contact forms)
URL fragments and hash parameters
HTTP headers (User-Agent, Referer)
File uploads with malicious filenames
API endpoints with insufficient validation

XSS Impact and Consequences

🔓 Session Hijacking

Attackers can steal session cookies and impersonate legitimate users, gaining unauthorized access to accounts.

📊 Data Theft

Sensitive user data, including personal information and financial details, can be extracted and sent to attackers.

🔄 Website Defacement

Attackers can modify website content, display fake information, or redirect users to malicious sites.

⚡ Malware Distribution

XSS can be used to deliver and execute malware on users' systems through drive-by downloads.

How to Prevent XSS Vulnerabilities

Protecting against XSS requires a multi-layered security approach:

Input Validation: Validate and sanitize all user inputs on both client and server sides
Output Encoding: Encode data before rendering it in HTML, JavaScript, or other contexts
Content Security Policy (CSP): Implement CSP headers to restrict script execution
HTTPOnly Cookies: Mark session cookies as HTTPOnly to prevent JavaScript access
Security Libraries: Use established security libraries instead of custom solutions
Regular Testing: Conduct security testing and code reviews regularly

XSS Testing Best Practices

Test all user-input points including forms, URLs, and headers
Use a variety of payloads targeting different contexts (HTML, JavaScript, CSS)
Test with encoding and obfuscation techniques
Verify both reflected and stored XSS vulnerabilities
Test across different browsers and devices
Follow responsible disclosure practices when finding vulnerabilities

🔍 Recommended Security Tools

Enhance your security testing with these trusted tools and platforms:

Burp Suite

Web Vulnerability Scanner

OWASP ZAP

Open Source Security Tool

Nessus

Vulnerability Assessment

Metasploit

Penetration Testing

Acunetix

Web Application Security