CSP: font-src

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

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

http

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

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