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Font Subset

Generate smaller font files by keeping only the glyphs your project actually needs.

Font subsetting is one of WebFont's most important production features. It can cut web font payloads dramatically, especially for large CJK fonts, multilingual UI fonts, and product interfaces that only need a controlled character set.

What it creates

  • Smaller TTF/OTF (original outlines), WOFF, and WOFF2 outputs.
  • Browser-ready web font files for focused character sets.
  • Subsets based on selected glyphs, text input, imported .txt files, Unicode presets, or filtered glyph ranges.
  • Subsets from TrueType, CFF/CFF2, variable, and color fonts, including one selected TTC/OTC face.

Source modes

Current Selection

Use the glyph browser to search, filter, and select the glyphs you want to keep. This is useful for icon-like sets, UI symbol groups, or carefully curated glyph ranges.

Text Input

Paste the exact text your project uses, or import a .txt file. WebFont matches the available Unicode characters in the loaded font and builds a subset from that text.

Unicode presets and filtering

WebFont includes Unicode-oriented filtering for common production needs, including General, Japanese, and Korean presets. You can also use block-based filtering in the glyph browser to narrow large fonts before creating a subset.

Output formats

Choose any combination of:

  • TTF / OTF (original outlines)
  • WOFF
  • WOFF2

TTF/OTF (original outlines) keeps the source outline type: TrueType sources produce .ttf, CFF/CFF2 sources produce .otf. WOFF2 is usually the best web delivery target, WOFF is useful for broader compatibility, and desktop outlines are useful when you need an editable or app-embedded font file.

Static instances

For variable fonts, the Export panel shows a Variable Font section.

  • Keep all axes exports the variable font and keeps interactive axes in the web demo where supported.
  • Static instance reveals sliders, numeric fields, reset, and a live text preview, then bakes the current axis values into Font Subset and Web Package outputs. Unlisted axes are pinned to their defaults, and the font's name and weight/style metadata are not rewritten. Glyph asset export is unchanged.

OpenType controls

Subset output can preserve or reduce OpenType layout data depending on your target.

  • Preserve all layout features.
  • Keep essential positioning only.
  • Remove layout tables.
  • Keep or remove selected OpenType feature tags.

Use conservative settings when working with scripts that rely on shaping, ligatures, marks, or positioning.

Preview and validation

Before export, WebFont shows subset metrics such as glyph count, estimated output size, and missing character count.

Generated outputs are validated for parser compatibility, required tables, cmap coverage, duplicate Unicode mappings, and WOFF/WOFF2 round-trip behavior.

Best practices

  • Use text input for real UI copy, landing pages, and fixed product strings.
  • Use current selection for manual curation and symbol-focused fonts.
  • Keep layout features when subsetting complex scripts.
  • Test the exported subset in the page or app where it will be used.
  • Keep the original full font separately so the subset can be regenerated later.

Current boundaries

  • Subset generation supports one loaded source font or one selected TTC/OTC face at a time.
  • Subset outputs keep the source outline type (TrueType → .ttf, CFF/CFF2 → .otf); WOFF and WOFF2 remain web containers.
  • Missing characters are reported, but WebFont does not invent glyphs that are not present in the source font.