How to convert ttf or otf to woff online for free
- Step 1Drop your TTF or OTF file — Drag any TrueType or OpenType font into the converter. The format is auto-detected from the magic bytes — extension renaming doesn't matter.
- Step 2We zlib-deflate each table — Per the WOFF spec, each font table is independently zlib-compressed (or kept raw if compression doesn't reduce size). The pako library does this in pure JS, fast.
- Step 3Download the WOFF — The result includes the original size, compressed size, and reduction ratio. Drop the .woff file into your @font-face src list — works in every browser since IE9.
Frequently asked questions
When should I prefer WOFF over WOFF2?+
Almost never in 2026 — WOFF2 has 99%+ support. The exception is when you must support IE11 (some enterprise intranets). Even then, ship WOFF2 first and WOFF as a src fallback so 99% of users get the smaller file.
What's the file size difference?+
WOFF is typically 30–40% smaller than TTF and 25–35% larger than WOFF2. For a 200 KB TTF: WOFF ≈ 130 KB, WOFF2 ≈ 95 KB.
Does WOFF preserve OpenType features?+
Yes. WOFF is a lossless wrapper — every OpenType table (cmap, glyf, GSUB, GPOS, kern, COLR/CPAL) is preserved byte-for-byte. Only the wire format changes.
Can I round-trip back to TTF?+
Yes. The decompressed WOFF tables reconstitute a TTF identical to the source (modulo metadata). For browser conversion, use the JAD WOFF2-to-TTF tool with a WOFF2-wrapped version of your font.
Privacy first
Every JAD Font tool runs entirely in your browser using opentype.js and the wawoff2 WASM Brotli encoder. Your fonts never leave your device — verified by zero outbound network requests during processing.