Platform Guide

How to Add Security Headers on Netlify

Add CSP, HSTS, X-Frame-Options, X-Content-Type-Options, Referrer-Policy, and Permissions-Policy to Netlify. Copy-paste configuration included.

The 6 Essential Security Headers

Content-Security-Policy (CSP)

Controls which sources of scripts, styles, and resources are allowed. Prevents XSS by blocking inline scripts and unauthorized external scripts.

Strict-Transport-Security (HSTS)

Forces browsers to always use HTTPS, preventing protocol downgrade attacks and cookie hijacking over HTTP.

X-Frame-Options

Prevents your page from being loaded in an iframe, blocking clickjacking attacks.

X-Content-Type-Options

Prevents browsers from MIME-sniffing the content type, stopping attacks that rely on content type confusion.

Referrer-Policy

Controls how much referrer information is sent with requests, protecting user privacy and preventing information leakage.

Permissions-Policy

Controls which browser features (camera, microphone, geolocation) your page can use, reducing attack surface.

Netlify Configuration

Add this to public/_headers file in your project (deployed to publish directory), or [[headers]] section in netlify.toml:

# public/_headers (place in your publish directory)
/*
  X-Frame-Options: DENY
  X-Content-Type-Options: nosniff
  Strict-Transport-Security: max-age=63072000; includeSubDomains; preload
  Referrer-Policy: strict-origin-when-cross-origin
  Permissions-Policy: camera=(), microphone=(), geolocation=()
  Content-Security-Policy: default-src 'self'; script-src 'self' 'unsafe-inline'; style-src 'self' 'unsafe-inline';
  X-XSS-Protection: 1; mode=block

The _headers file must be in your publish directory (usually 'public' or 'dist'). Netlify automatically provides HTTPS. Headers apply to all paths matching the pattern (/* = all pages).

How to Test Your Headers

curl -I https://your-site.netlify.app

Or use Cybrove's free security check to automatically validate all security headers and get specific fix recommendations.

Complete guide to fixing missing security headers

In-depth blog post covering all headers across all platforms

Frequently Asked Questions

How do I add security headers to Netlify?

Add security headers to Netlify by modifying public/_headers file in your project (deployed to publish directory), or [[headers]] section in netlify.toml. The essential headers are CSP, HSTS, X-Frame-Options, X-Content-Type-Options, Referrer-Policy, and Permissions-Policy. See the configuration example above.

How do I test if my Netlify security headers are working?

Run: curl -I https://your-site.netlify.app and check the response headers. Or use Cybrove's free security check at cybrove.com/scan which automatically validates all security headers and reports which are missing.

Which security headers are most important for Netlify?

CSP (prevents XSS), HSTS (forces HTTPS), and X-Frame-Options (prevents clickjacking) are the most critical. X-Content-Type-Options and Referrer-Policy provide additional protection with minimal configuration effort.

Check if your Netlify headers are configured correctly

Free security check validates all 6 headers plus SSL, DNS, and email authentication.

Free Security Check