Font subsetting removes unused characters (glyphs) from a font file. This drastically reduces file size, often by 70-90%, which improves website loading speed and saves bandwidth. It's essential for web performance when using custom fonts that contain many languages or symbols you don't need.

Our tool supports TTF, OTF, WOFF, and WOFF2 files as input. You can output to any of these formats, with WOFF2 recommended for modern web use due to superior compression.

Check your website content: include all letters, numbers, punctuation, and special characters that appear in your text. Our presets cover common cases. For multilingual sites, make sure you include necessary diacritics and localized characters.

Absolutely. All processing happens directly in your browser using client-side technology. Your font files are never uploaded to any server, ensuring complete privacy and compliance with font licenses.

No. The remaining characters are identical to the original; only unused glyphs are removed. Hinting, kerning, and OpenType features are preserved for the kept characters.

Yes. Many Google Fonts contain hundreds of characters. If you only use basic Latin, you can further reduce the file size by subsetting. The same applies to any other web font.