Firefox's preference is "font.system.whitelist". You can specify a list of which fonts are exposed to web content (such as the default set shipped with your OS)

Firefox's preference is "font.system.whitelist". You can specify a list of which fonts are exposed to web content (such as the default set shipped with your OS). The preference is used by the Tor browser. https://bugzilla.mozilla.org/show_bug.cgi?id=1121643 https://bugzilla.mozilla.org/show_bug.cgi?id=1121643 Does Safari actually do something similar? On my Mac, amiunique.org reports 344 fonts in Safari, 331 in Firefox (not using "font.system.whitelist"), and 309 in Chrome.