CSP: frame-src
Baseline Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since August 2016.
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
Content-Security-Policy: frame-src 'none';
Content-Security-Policy: frame-src <source-expression-list>;
This directive may have one of the following values:
'none'-
No resources of this type may be loaded. The single quotes are mandatory.
<source-expression-list>-
A space-separated list of source expression values. Resources of this type may be loaded if they match any of the given source expressions.
Source expressions are specified as keyword values or URL patterns: the syntax for each source expression is given in CSP Source Values.
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
BCD tables only load in the browser