WOFF2 files are purpose-built for the web — compressed with Brotli and reorganized for small transfer size — but that same compression makes them unusable anywhere a tool expects an ordinary desktop font. Font editors, operating system font installers, and some design software all expect the underlying SFNT format (TTF or OTF), not the compressed web wrapper. This tool reverses a WOFF2 file back into a standard, installable TTF.
The conversion is a decompression, not a re-interpretation — it uses Google's own reference WOFF2 decoder (compiled to WebAssembly) to undo the Brotli compression and reverse the glyf/loca table transform WOFF2 applies, recovering the exact original SFNT font data byte-for-byte. Nothing about the font's glyphs, metrics, or hinting is altered; the file is simply unpacked back into its pre-compression form.
This matters most when you only have the web-distributed version of a font — maybe you extracted it from a website's assets, or a design handoff only included the WOFF2 — and need a version you can actually install on your desktop, open in a font editor, or feed into a different conversion pipeline that doesn't understand WOFF2 directly.
Need to go the other way and prepare a font for the web? Use TTF to WOFF2.