CSP: font-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) font-src directive specifies valid sources for fonts loaded using @font-face.

CSP version 1
Directive type Fetch directive
default-src fallback Yes. If this directive is absent, the user agent will look for the default-src directive.

Syntax

http
Content-Security-Policy: font-src 'none';
Content-Security-Policy: font-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. For this directive, the following source expression values are applicable:

Examples

Violation cases

Given this CSP header:

http
Content-Security-Policy: font-src https://example.com/

The following font resource loading is blocked and won't load:

html
<style>
  @font-face {
    font-family: "MyFont";
    src: url("https://not-example.com/font");
  }
  body {
    font-family: "MyFont";
  }
</style>

Specifications

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

Browser compatibility

BCD tables only load in the browser

See also