CSP Header Generator: Free Online Content Security Policy Builder — How-To Guide

A Content Security Policy (CSP) is one of the most effective ways to protect a website from cross-site scripting (XSS) and code-injection attacks. Instead of hoping no malicious script ever reaches your pages, a CSP tells the browser exactly which sources are allowed to load scripts, styles, images, frames, fonts, and network requests — and blocks everything else. The hard part is writing the policy itself: one typo or one missing source, and your analytics, fonts, or embeds silently break.

The CSP Header Generator from ToolsFam builds a starter Content-Security-Policy header for you, based on your choices, so you can stop guessing at syntax and start with a policy you can actually test.

Try it free: CSP Header Generator

What the Tool Does

The CSP Header Generator creates a starter Content-Security-Policy header tailored to the kind of site you run — a static site, a SaaS dashboard, documentation pages, or a general web app. It handles the directive syntax for you (default-src, script-src, style-src, img-src, and more) and produces copyable output you can paste into your server configuration or test in report-only mode first.

It is useful for:

• Security reviews — produce a baseline policy to compare against what a site currently sends.
• New projects — ship a stricter default from day one instead of bolting on a policy later.
• Hardening static sites — blogs, docs, and marketing pages usually need only a few sources, so a generator gets you to a tight policy quickly.
• Learning CSP — seeing a complete, valid header makes the directive model much easier to understand than reading the spec alone.

How to Use It (Step by Step)

1. Open the tool. Go to the CSP Header Generator in your browser. No account, no signup, no installation.
2. Describe your site's needs. Choose the options that match your application: what kind of content it serves, which third parties it loads (analytics, fonts, embeds), and whether you rely on inline scripts or styles.
3. Generate the header. The tool composes a starter Content-Security-Policy header from your choices. Review each directive and make sure the allowed sources match what your pages actually load.
4. Test in report-only mode first. Deploy the policy as Content-Security-Policy-Report-Only and watch the violation reports in your browser's dev tools. This shows you what would have been blocked — without breaking the site for real users.
5. Tighten and enforce. Once the reports stop showing legitimate resources being flagged, switch the header to enforced Content-Security-Policy mode and monitor for a while.

Practical Tips

• Start strict, then loosen deliberately. A locked-down policy that you relax one source at a time is far safer than a permissive policy you never get around to tightening.
• Avoid unsafe-inline for scripts. Inline scripts are a favorite XSS vector. If your framework supports it, use nonces or hashes for the few inline scripts you truly need instead of opening the door to all of them.
• Pair CSP with other headers. A Content Security Policy works best alongside Strict-Transport-Security, Referrer-Policy, and X-Content-Type-Options. The tool's page recommends the same combination.

FAQ

Will a CSP stop all XSS attacks?
No. A Content Security Policy greatly reduces the impact of injection flaws and blocks many attack paths, but it is not a substitute for secure coding, input validation, and output escaping. Think of it as a safety net, not a fix for vulnerable code.

What is report-only mode?
Report-only mode (Content-Security-Policy-Report-Only) tells the browser to log policy violations without blocking anything. It is the recommended way to test a new policy: you collect real-world data about what your site loads, tune the policy until the reports are clean, and only then enforce it.

Should I allow unsafe-inline?
Avoid it when you can. Permitting all inline scripts and styles reopens much of the attack surface that CSP is meant to close. Modern frameworks usually let you attach nonces or hashes to the specific inline blocks you need, which keeps everything else locked down.

Can a strict policy break my site?
Yes — an overly strict policy can silently block analytics, web fonts, embedded videos, or inline scripts, which is exactly why report-only mode exists. Generate the starter policy, test it, review the violations, and only enforce it once every expected source is covered.

Privacy Note

Everything happens locally: the CSP Header Generator runs 100% in your browser, so your site details and generated policy never leave your device. Nothing is uploaded, stored on a server, or shared with anyone.

Ready to harden your site? Try it free: CSP Header Generator