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CSP: frame-src

CSP: frame-src

The HTTP Content-Security-Policy (CSP) frame-src directive specifies valid sources for nested browsing contexts loading using elements such as <frame> and <iframe>.

Note: frame-src allows you to specify where iframes in a page may be loaded from. This differs from frame-ancestors, which allows you to specify what parent source may embed a page.

CSP version 1
Directive type Fetch directive
Fallback If this directive is absent, the user agent will look for the child-src directive (which falls back to the default-src directive).

Syntax

One or more sources can be allowed for the frame-src policy:

Content-Security-Policy: frame-src <source>;
Content-Security-Policy: frame-src <source> <source>;

Sources

<source> can be any one of the values listed in CSP Source Values.

Note that this same set of values can be used in all fetch directives (and a number of other directives).

Examples

Violation cases

Given this CSP header:

Content-Security-Policy: frame-src https://example.com/

The following <iframe> is blocked and won't load:

<iframe src="https://not-example.com/"></iframe>

Specifications

Specification
Content Security Policy Level 3
# directive-frame-src

Browser compatibility

Desktop Mobile
Chrome Edge Firefox Internet Explorer Opera Safari WebView Android Chrome Android Firefox for Android Opera Android Safari on IOS Samsung Internet
frame-src
25
14
23
No
15
7
Yes
Yes
23
Yes
7
Yes

See also

© 2005–2022 MDN contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Security-Policy/frame-src