Content Security Policy (CSP) Builder
Build, configure, and validate HTTP Content-Security-Policy headers for web security.
Content Security Policy Builder
Content-Security-Policy: default-src 'self'; script-src 'self' 'unsafe-inline'; style-src 'self' 'unsafe-inline'; img-src 'self' data: https:;
About Content Security Policy (CSP) Builder
The Content Security Policy (CSP) Header Builder configures HTTP security policy directives (`default-src`, `script-src`, `style-src`, `img-src`, `connect-src`, `frame-ancestors`) to defend web applications against Cross-Site Scripting (XSS) and clickjacking attacks.
How to Use Content Security Policy (CSP) Builder
Step 1
Select source rules and allowed domains for each resource type.
Step 2
Add third-party CDN or API domains (e.g. Google Analytics, Stripe).
Step 3
Preview the generated `Content-Security-Policy` header in real time.
Step 4
Copy the header into your server configuration or Next.js middleware.
Practical Use Cases for Content Security Policy (CSP) Builder
Defending Web Applications from XSS Attacks
Block unauthorized JavaScript injection and malicious external scripts by whitelisting trusted origins and script hashes.
Clickjacking & Framing Protection
Replace legacy `X-Frame-Options` with modern `frame-ancestors 'none'` or explicit domain whitelists.
Input & Output Examples
Building Strict Next.js CSP Policy
default-src: 'self', script-src: 'self' https://apis.google.com, style-src: 'self' 'unsafe-inline'
Content-Security-Policy: default-src 'self'; script-src 'self' https://apis.google.com; style-src 'self' 'unsafe-inline';
Key Features & Performance
- ✓Interactive policy editor for 15+ CSP directives: `default-src`, `script-src`, `style-src`, `img-src`, `font-src`, `connect-src`, `frame-src`, `frame-ancestors`.
- ✓Supports special source keywords: `'self'`, `'unsafe-inline'`, `'unsafe-eval'`, `'none'`, `https:`, and `data:`.
- ✓Outputs HTTP Header format, HTML `<meta>` tag format, and NGINX / Apache configs.
- ✓100% Client-Side configuration.
- ✓1-Click Copy CSP string.
Key Terminology & Definitions
Content Security Policy (CSP)
An HTTP response header that restricts the resources (scripts, images, stylesheets) that the browser is allowed to load for a given page.
CSP Nonce
A cryptographically random number generated per HTTP request used to allow specific inline `<script>` tags without using `'unsafe-inline'`.