Content Security Policy

Last updated May 5, 2026 If your website uses a Content Security Policy (CSP) ↗︎ header, you must configure it to allow Turnstile's scripts and iframes. Without the correct CSP directives, Turnstile may fail to load.

Cloudflare recommends using the nonce-based approach documented with CSP3 ↗︎. Include your nonce in the api.js script tag and Turnstile will propagate it to dynamically loaded resources. Turnstile works with strict-dynamic ↗︎.

Alternatively, add the following values to your CSP header:

  • script-src: https://challenges.cloudflare.com
  • frame-src: https://challenges.cloudflare.com

We recommend validating your CSP with Google's CSP Evaluator ↗︎.

Note

You cannot set your own CSP and/or Referer-Policy via meta tags or Transform rules in challenge pages.

Pre-clearance support

If you are using Turnstile in pre-clearance mode, Turnstile sets the cf_clearance cookie by doing a fetch request to a special endpoint in /cdn-cgi/ of your domain.

For this request to succeed, your connect-src directive must include 'self'.

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description: Browser compatibility for challenge pages, Turnstile, and JavaScript detections. title: Supported browsers image: https://developers.cloudflare.com/cloudflare-challenges/reference/supported-browsers/og.png?v=c1516a20bff18f78

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