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XSS DEFENSE / FREE DAST AUDITOR

Free Online Content Security Policy (CSP) Evaluator

Validate your CSP directives against Cross-Site Scripting (XSS) and code injection.

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Standard
W3C CSP Level 3
Primary Defense
Stored, Reflected & DOM-based XSS
Key Directive
default-src 'self'
Framework Compatibility
Next.js, Express, Nginx, Cloudflare

Why Missing CSP Leaves Modern Web Applications Vulnerable to XSS

Cross-Site Scripting (XSS) remains the #1 client-side attack vector. A robust Content-Security-Policy restricts the domains from which scripts, styles, images, and fonts can load, rendering injected script payloads completely inert.

Production-Ready Remediation Snippets

Select your deployment environment below and copy the tailored configuration snippet to enforce compliance immediately:

Nginx
# /etc/nginx/conf.d/csp.conf
add_header Content-Security-Policy "default-src 'self'; script-src 'self' 'unsafe-inline' https://cdnjs.cloudflare.com; style-src 'self' 'unsafe-inline' https://fonts.googleapis.com; font-src 'self' https://fonts.gstatic.com; img-src 'self' data: https:;" always;

Frequently Asked Questions

What does Content-Security-Policy do?

CSP tells the browser which trusted sources of content are allowed to load and execute on your page, effectively blocking unauthorized malicious scripts and data exfiltration.

Why should I avoid unsafe-inline in script-src?

Using unsafe-inline allows any inline script tag to execute, which eliminates the core protection CSP provides against Cross-Site Scripting (XSS).

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