Content-Security-Policy: block-all-mixed-content directive

[!WARNING] This directive is marked as obsolete in the specification. This directive was previously used to prevent “optionally blockable” mixed content from being fetched insecurely and displayed. Content that isn’t blocked is now always upgraded to a secure connection, so this directive is not needed.

The HTTP Content-Security-Policy (CSP) block-all-mixed-content directive prevents loading any assets over HTTP when the page uses HTTPS.

All mixed content resource requests are blocked, including both blockable and upgradable mixed content. This also applies to <iframe> documents, ensuring the entire page is mixed content-free.

[!NOTE] The upgrade-insecure-requests directive is evaluated before block-all-mixed-content. If the former is set, the latter does nothing, so set one directive or the other – not both, unless you want to force HTTPS on older browsers that do not force it after a redirect to HTTP.

Syntax

Content-Security-Policy: block-all-mixed-content;

Examples

Content-Security-Policy: block-all-mixed-content;

<meta http-equiv="Content-Security-Policy" content="block-all-mixed-content">

To disallow http assets on a more granular level, you can also set individual directives to https:. For example, to disallow insecure HTTP images:

Content-Security-Policy: img-src https:

Specifications

Browser compatibility

See also

• Content-Security-Policy
• upgrade-insecure-requests
• Mixed content