CSP Builder

New

Build a Content-Security-Policy header with a clean UI.

100% private — no uploads Developer ToolsFree & unlimited Read tutorial

See how it works

Watch a quick simulation of this tool in action — no file needed.

How to use CSP Builder

Follow these steps — everything happens instantly in your browser.

  1. 1

    Step 1. Add or edit directives — default-src, script-src, style-src and more.

  2. 2

    Step 2. Toggle upgrade-insecure-requests and (optionally) report-uri.

  3. 3

    Step 3. Copy either the HTTP header or the meta tag version.

Why use this tool

Private by design

All processing happens locally in your browser. Open DevTools → Network and you'll see zero file uploads. Ever.

Instant

No upload wait, no queue, no server round-trip. Results appear the moment you drop a file.

Free & unlimited

No accounts, no watermarks, no daily caps. Use it as many times as you like, forever.

Works everywhere

Desktop, tablet or phone — every tool is responsive and installable as a PWA for offline use.

Frequently asked questions

Everything you might want to know about csp builder.

Want to learn more?

Read our complete CSP Builder tutorial with tips, use cases, and FAQs.