FontData

Limited availability

This feature is not Baseline because it does not work in some of the most widely-used browsers.

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.

Instance properties

FontData.family Read only Experimental

Returns the family of the font face.

FontData.fullName Read only Experimental

Returns the full name of the font face.

FontData.postscriptName Read only Experimental

Returns the PostScript name of the font face.

FontData.style Read only Experimental

Returns the style of the font face.

Instance methods

FontData.blob() Experimental

Returns a Promise that fulfills with a Blob containing the raw bytes of the underlying font file.

Examples

For a working live demo, see Font Select Demo.

Font enumeration

The following snippet will query for all available fonts, and log metadata. This could be used, for example, to populate a font-picker control.

js
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);
  }
}

Accessing low-level data

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).

js
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);
  }
}

Specifications

Specification
Local Font Access API
# fontdata-interface

Browser compatibility

Report problems with this compatibility data on GitHub
desktopmobile
Chrome
Edge
Firefox
Opera
Safari
Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
WebView on iOS
FontData
Experimental
blob
Experimental
family
Experimental
fullName
Experimental
postscriptName
Experimental
style
Experimental

Legend

Tip: you can click/tap on a cell for more information.

Full support
Full support
No support
No support
Experimental. Expect behavior to change in the future.
See implementation notes.

See also