Experimental: This is an experimental technology
Check the Browser compatibility table carefully before using this in production.
The FontData interface of the Local Font Access API represents a single local font face.
FontData.family Read only Returns the family of the font face.
FontData.fullName Read only Returns the full name of the font face.
FontData.postscriptName Read only Returns the PostScript name of the font face.
FontData.style Read only Returns the style of the font face.
FontData.blob() Returns a Promise that fulfills with a Blob containing the raw bytes of the underlying font file.
For a live example, see our Local Font Access API demo.
The following snippet will query for all available fonts, and log metadata. This could be used, for example, to populate a font-picker control.
async function logFontData() {
try {
const availableFonts = await window.queryLocalFonts();
for (const fontData of availableFonts) {
console.log(fontData.postscriptName);
console.log(fontData.fullName);
console.log(fontData.family);
console.log(fontData.style);
}
} catch (err) {
console.error(err.name, err.message);
}
}The blob() method provides access to low-level SFNT data — this is a font file format that can contain other font formats, such as PostScript, TrueType, OpenType, or Web Open Font Format (WOFF).
async function computeOutlineFormat() {
try {
const availableFonts = await window.queryLocalFonts({
postscriptNames: ["ComicSansMS"],
});
for (const fontData of availableFonts) {
// `blob()` returns a Blob containing valid and complete
// SFNT-wrapped font data.
const sfnt = await fontData.blob();
// Slice out only the bytes we need: the first 4 bytes are the SFNT
// version info.
// Spec: https://learn.microsoft.com/en-us/typography/opentype/spec/otff#organization-of-an-opentype-font
const sfntVersion = await sfnt.slice(0, 4).text();
let outlineFormat = "UNKNOWN";
switch (sfntVersion) {
case "\x00\x01\x00\x00":
case "true":
case "typ1":
outlineFormat = "truetype";
break;
case "OTTO":
outlineFormat = "cff";
break;
}
console.log("Outline format:", outlineFormat);
}
} catch (err) {
console.error(err.name, err.message);
}
}