1.0 KiB
Font Tools
Font Tools is a GPL-3.0-or-later, local-first browser workbench for inspecting TTF, OTF and WOFF fonts. It inventories SFNT tables, names, metrics, Unicode coverage, variable axes and OS/2 embedding restrictions; previews arbitrary text against local fallbacks; generates inert CSS; and can rebuild a deliberately simple static outline subset when the machine-readable restrictions permit it.
Files never leave the browser. Parsing and subsetting run in a disposable worker with an 8-second operation limit. Preview rendering is contained in a scriptless sandboxed frame. WOFF2 is detected but not parsed in v0.1.0.
Limits: 16 MiB input, 64 MiB declared expanded SFNT size, 128 tables, 65,535 glyphs, 250,000 Unicode mappings, 20,000 preview characters and 1,024 subset glyphs. Suspicious WOFF ratios and invalid table bounds are rejected before the font library sees the data.
Run npm ci, then npm run check, npm run test:browser, and
npm run package:release -- --force. Copyright © 2026 Albrecht Degering.