noto-fonts-dl

Download and embed Google Noto fonts at build time with Cargo feature flags. 134 languages/scripts supported — just enable the ones you need.

• Fonts are downloaded from Google Fonts at compile time (cached for subsequent builds)
• All selected fonts are compressed together into a single XZ bundle
• Decompressed in memory at runtime (~0.5s for the largest bundles)
• Zero font files stored in the crate itself
• Language-to-font mapping derived from Android's official Noto configuration

Quick Start

[dependencies]
noto-fonts-dl = { version = "0.1", features = ["ko", "ar", "hi"] }

let fonts = noto_fonts_dl::load_fonts();
for (lang, data) in fonts {
    println!("{}: {} bytes", lang, data.len());
}

Integration with egui

use eframe::egui;
use std::sync::Arc;

// In your eframe App setup:
let fonts_data = noto_fonts_dl::load_fonts();

let mut fonts = egui::FontDefinitions::default();
for (name, data) in fonts_data {
    fonts.font_data.insert(
        name.clone(),
        Arc::new(egui::FontData::from_owned(data.clone())),
    );
    // Add as fallback after the default font
    fonts.families
        .entry(egui::FontFamily::Proportional)
        .or_default()
        .push(name.clone());
}
ctx.set_fonts(fonts);

Integration with other frameworks

load_fonts() returns &Vec<(String, Vec<u8>)> — a list of (language_code, raw_ttf_bytes) pairs. Use the raw bytes with any font loading API:

iced

let fonts = noto_fonts_dl::load_fonts();
for (_, data) in fonts {
    iced::font::load(data.clone());
}

wgpu-text / glyph-brush

let fonts = noto_fonts_dl::load_fonts();
for (_, data) in fonts {
    let font = ab_glyph::FontArc::try_from_vec(data.clone()).unwrap();
    glyph_brush.add_font(font);
}

Any framework

The font data is standard TrueType/OpenType — it works with any library that accepts &[u8] font data: fontdue, rusttype, cosmic-text, swash, ab_glyph, etc.

Available Features

Common Languages

Symbols & Emoji

The feature codes zsye and zsym come from ISO 15924 script codes. Zsye stands for "Symbols (emoji variant)" — the standard script subtag for color emoji presentation. Zsym stands for "Symbols" — for monochrome symbol glyphs. These are not language codes but script codes used in BCP 47 to distinguish emoji rendering from plain text symbols.

Convenience Groups

100+ Additional Scripts

The crate supports 134 scripts total, including historical and rare writing systems (Cuneiform, Egyptian Hieroglyphs, Runic, Gothic, etc.). See Cargo.toml for the full list.

How It Works

1. Build time: build.rs reads fonts.json (a mapping from language codes to Noto font filenames, derived from Android's official configuration)
2. Download: For each enabled feature, downloads the corresponding font from Google Fonts (with fallback to the notofonts GitHub repository for CJK)
3. Cache: Downloaded fonts are cached in OUT_DIR — subsequent builds don't re-download
4. Compress: All fonts are packed into a minimal binary format and compressed with XZ (~50-60% compression ratio)
5. Embed: The compressed bundle is embedded in the binary via include_bytes!
6. Runtime: load_fonts() decompresses the bundle on first call (~0.5s) and returns the font data. Cached via OnceLock for instant subsequent calls.

Bundle Sizes

Requirements

• Internet connection at build time (first build only — fonts are cached)
• No runtime dependencies beyond xz2 for decompression

License

MIT OR Apache-2.0

Noto fonts are licensed under the SIL Open Font License.