AVAILABLE FOR WEB, FLUTTER & QA PROJECTS

How to use this tool

1. Select Security Profile

Pick Strict Nonce-Based, Balanced SaaS, or Permissive Starter policy.

2. Configure Core Directives

Customize default-src, script-src, style-src, img-src, connect-src, and frame-ancestors.

3. Whitelist Trusted Services

Toggle common providers like Google Analytics, Stripe, Google Fonts, and Vercel.

4. Export Header Syntax

Copy HTTP header string, Next.js middleware code, or HTML <meta> tag.

Formula or logic used

CSP Policy Structure & Directive Grammar

Constructs granular resource origin rules enforcing browser execution boundaries and blocking unauthorized code injection.

  • default-src 'self' defines fallback permissions for all unspecified resource types
  • script-src 'self' 'nonce-{RANDOM}' 'strict-dynamic' prevents malicious inline script execution
  • frame-ancestors 'none' blocks unauthorized embedding in iframes, preventing clickjacking attacks
  • connect-src restricts destinations for fetch(), XMLHttpRequest, and WebSocket connections

Examples

Example 1: Modern Next.js App Router Policy

Input: Services: Google Fonts + Stripe Checkout + Google Analytics 4
Calculated Result: Content-Security-Policy: default-src 'self'; script-src 'self' 'unsafe-inline' https://js.stripe.com https://www.googletagmanager.com; connect-src 'self' https://api.stripe.com https://www.google-analytics.com; img-src 'self' data: https:; font-src 'self' https://fonts.gstatic.com; style-src 'self' 'unsafe-inline' https://fonts.googleapis.com; frame-ancestors 'none';

Safeguards user authentication and payment data while permitting necessary third-party checkout scripts.

Example 2: High-Security Enterprise Banking Policy

Input: Strict Nonce-Based with Zero Inline Eval
Calculated Result: Content-Security-Policy: default-src 'none'; script-src 'self' 'nonce-rAnd0m123' 'strict-dynamic'; object-src 'none'; base-uri 'none'; frame-ancestors 'none'; form-action 'self';

Maximum OWASP-compliant lockdown blocking all unauthorized inline scripts and domain spoofing.

Common use cases

XSS Vulnerability Mitigation

Neutralize stored and reflected Cross-Site Scripting attacks even if unescaped user input reaches the DOM.

PCI-DSS Compliance Audits

Fulfill PCI-DSS 4.0 requirements regarding script integrity on payment checkout pages.

Clickjacking Defense

Prevent malicious actors from embedding your application inside transparent iframe overlays.

Next.js Security Header Integration

Generate dynamic nonce headers in Next.js middleware for zero-trust script execution.

Web Developer Tools

Cache-Control Header Generator

The Cache-Control Header Generator creates standardized HTTP caching directives instructing browsers and CDN e...

Launch Tool →
Web Developer Tools

HSTS Preload Readiness Checker

The HSTS Preload Readiness Checker audits your domain's Strict-Transport-Security header against the official ...

Launch Tool →
WordPress & CMS Tools

WordPress Security Header Checker

The WordPress Security Header Checker inspects live WordPress websites and raw HTTP response headers against m...

Launch Tool →

Frequently asked questions

What is the difference between CSP and CSP-Report-Only?

Content-Security-Policy enforces the rules and blocks any violating resource from executing. Content-Security-Policy-Report-Only allows violating resources to run normally, but reports each violation to a reporting endpoint, allowing safe testing in production.

Why should I avoid 'unsafe-inline' and 'unsafe-eval'?

'unsafe-inline' allows any inline <script> tag to run, effectively disabling CSP's primary defense against Cross-Site Scripting (XSS). 'unsafe-eval' allows strings to be converted into executable code via eval(), opening dangerous code injection pathways.

How does strict-dynamic work in CSP Level 3?

'strict-dynamic' allows a script that was loaded with a valid cryptographic nonce to load additional downstream scripts without needing to whitelist every transitive domain.

Can CSP be declared inside an HTML <meta> tag?

Yes, via <meta http-equiv='Content-Security-Policy' content='...'>. However, frame-ancestors, report-uri, and sandbox directives are ignored when delivered through meta tags; they require true HTTP headers.

Blueprint Grid Background
AVAILABLE FOR NEW CONTRACTS & ARCHITECTURAL BUILDS

Let's build something
exceptional together

Work directly with Faisal Rafique to architect and deliver high-performance Next.js 15 platforms, 60fps Flutter mobile applications, and enterprise automated QA testing pipelines.

Direct Senior Architect Access
100% Code & IP Ownership
Milestone-Based Global Delivery