FontFaceSet.check()

The check() method of the FontFaceSet returns whether all fonts in the given font list have been loaded and are available.

bool = aFontFaceSet.check(font);
bool = aFontFaceSet.check(font, text);

A Boolean that is true if the font list is available

• font: a font specification using the CSS value syntax, e.g. "italic bold 16px Roboto"
• text: limit the font faces to those whose Unicode range contains at least one of the characters in text. This does not check for individual glyph coverage.

document.fonts.check("12px courier"); // returns true if the font courier is available at 12px

document.fonts.check("12px MyFont", "ß"); // returns true if the font 'MyFont' has a ß character.