GlyphProof — Font Glyph Coverage Preflight

Catch missing glyphs before your users see □ boxes.

GlyphProof compares the actual text in your project against the TTF / OTF fonts you plan to ship.

Instead of asking whether a font “supports Japanese” or “supports Unicode,” it answers the practical question:

Does this font contain every character my project actually uses?

Useful for game dialogue, UI strings, localization, subtitles, captions, and video titles.

GlyphProof is a local browser utility for checking whether your actual project text is fully covered by the TTF / OTF fonts you plan to ship.

Use real dialogue, subtitles, UI strings, documentation, store text, or localization files and catch missing glyphs before release.

Features:

- Direct Unicode cmap parsing for TTF / OTF fonts

- Multiple fonts checked as a fallback chain

- Missing-character detection

- Unicode code points

- Occurrence counts

- File / line examples

- Per-font coverage

- Unique-character coverage percentage

- Copy all missing characters

- CSV / TXT reports

Text inputs:

- TXT

- CSV / TSV

- JSON

- SRT / VTT

- ASS / SSA

- Markdown

- HTML / XML

- Pasted text

Supported text decoding:

- UTF-8

- Shift_JIS / CP932

- UTF-16 LE

- UTF-16 BE

Useful for:

- Game UI and dialogue

- Localization

- Subtitles and captions

- Video titles

- Visual novels

- Web projects

- Font selection

- Pre-release QA

Privacy & safety:

- Runs entirely locally

- No font uploads

- No text uploads

- No external API

- Does not modify source files

- No installation required

- English / Japanese UI

Notes:

- TTC is not an officially supported input in v1.0.

- GlyphProof performs cmap-level coverage checks. Complex shaping and emoji-sequence rendering are outside its scope.

- ZWJ and variation selectors are ignored by default.