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CSP Policy Builder

Build a Content Security Policy header with source directives, reporting, nonce and security options.

Enforce and Report-Only modes Strict, WordPress, API and static presets Nonce and SHA hash sources Security warnings
Test new policies with Report-Only first. Avoid unsafe-inline and unsafe-eval whenever possible.
INPUT Policy mode
0 chars0 words0 lines
Generated CSP policy HTTP header, policy value, warnings, and optional HTML meta tag.
About the tool

What CSP Policy Builder does

CSP Policy Builder is a powerful online Content Security Policy generator for creating safer HTTP response headers without manually assembling every directive. Choose a practical preset, edit source lists, add a reporting endpoint, and generate a copy-ready Content-Security-Policy or Content-Security-Policy-Report-Only header.

The CSP Policy Builder supports common directives including default-src, script-src, style-src, img-src, font-src, connect-src, frame-src, object-src, base-uri, form-action, and frame-ancestors. It also recognizes nonce and SHA-256, SHA-384, or SHA-512 hash sources.

CSP Policy Builder interface for creating a Content Security Policy header
Build, review, and test a Content Security Policy before enforcement.

How to use

  1. Choose the policy mode. Start with Report-Only on an existing website.
  2. Select a preset. Use Strict, WordPress, API, Static, or Custom as the starting point.
  3. Review source directives. Keep each source list as narrow as possible.
  4. Add nonces or hashes. Prefer these over unsafe-inline for scripts and styles.
  5. Configure reporting. Add an HTTPS endpoint when violation reporting is available.
  6. Generate and test. Review browser console reports before switching to enforcement.
Built for the task

Why use CSP Policy Builder?

Focused controls, predictable output, and a workflow designed around this exact transformation.

01

Security-focused presets

Start from strict, WordPress, API, static, or custom policy configurations.

02

Nonce and hash support

Use nonce and SHA source expressions instead of broad inline-script permissions.

03

Visible warnings

Identify unsafe-inline, unsafe-eval, wildcard sources, and enforcement risks.

04

Copy-ready output

Generate an HTTP header, policy value, and supported meta-tag version.

Useful answers

Questions about CSP Policy Builder

Practical details about input, output, privacy, limits, and the best way to use this tool.

Answer 01

What is a CSP Policy Builder?

A CSP Policy Builder creates a Content Security Policy from selected directives and trusted source values, reducing syntax mistakes when preparing an HTTP security header.

Answer 01

What is a CSP Policy Builder?

A CSP Policy Builder creates a Content Security Policy from selected directives and trusted source values, reducing syntax mistakes when preparing an HTTP security header.

How CSP Policy Builder works

The CSP Policy Builder combines directive names with validated source expressions and produces a standards-oriented policy string. The generated output includes the complete HTTP header and a separate policy value for server configuration.

Content Security Policy reduces the browser locations from which scripts, styles, images, fonts, frames, and network connections may load. A narrow policy can limit the impact of injected markup, but CSP complements rather than replaces output escaping, sanitization, authentication, and secure coding.

12 important CSP Policy Builder controls

default-src supplies a fallback. script-src and style-src control executable scripts and styles. img-src and font-src cover visual assets. connect-src limits fetch, XHR, EventSource, and WebSocket connections. frame-src controls framed documents, while frame-ancestors controls who may frame your page.

object-src 'none', a narrow base-uri, and a restricted form-action are strong defaults for many applications. Review every source added by plugins, analytics, fonts, payment providers, embedded media, and API endpoints.

CSP nonces and cryptographic hashes

A nonce source has the form 'nonce-randomValue'. The value must be unpredictable and regenerated for each HTTP response. A matching nonce attribute authorizes the intended inline script or style.

Hash sources such as 'sha256-...' authorize exact inline content. Any content change requires a new hash. Nonces and hashes are normally safer than enabling 'unsafe-inline'.

Test with Report-Only before enforcement

Report-Only mode records violations without blocking resources. Exercise the site across login, checkout, account, admin, forms, embedded media, analytics, and third-party integrations. Investigate each violation rather than adding broad wildcards.

After reports stabilize, deploy the enforcement header gradually and continue monitoring. A policy that blocks critical scripts can break navigation, payment, authentication, or accessibility features.

Common CSP Policy Builder mistakes

Frequent mistakes include combining 'none' with other sources, allowing all domains with *, copying a static nonce into every response, using 'unsafe-eval' without necessity, and assuming a meta tag supports every directive.

Another mistake is defining only default-src and overlooking application-specific connections, frames, fonts, or form destinations. Use browser developer tools and CSP reports to discover legitimate dependencies.

Continue with HTTP Header Builder, cURL Builder, or OpenAPI Generator.

Authoritative CSP references

Review the MDN Content Security Policy guide and the W3C CSP Level 3 specification.