Convert fonts for the web
The right font format makes your site faster. WOFF2 is the modern standard, it is compressed with Brotli and is typically 30% smaller than WOFF and 40% smaller than TTF at the same quality. Every modern browser supports it, which is why it should be your default for web fonts.
TTF and OTF to WOFF2
TTF and OTF are the formats fonts are delivered in from foundries and design tools. Convert either to WOFF2 to cut file size dramatically before hosting it on your site or embedding it in an app.
WOFF and WOFF2 to TTF
Need to edit a font you downloaded from the web? Convert WOFF or WOFF2 back to TTF so it opens in desktop editors like FontForge, Glyphs, or your operating system's font manager.
What about OTF output?
OpenType fonts use two internal outlines: TrueType (glyf) and PostScript (CFF). When an OTF file is opened it is converted to TrueType outlines, so the output formats are TTF, WOFF, and WOFF2. Your OTF still converts cleanly, it just lands as TTF or a web format.