OTC to WOFF Converter
Processing entirely on your device — large files may take a moment.
OTC is the CFF-flavored OpenType collection — the same ttcf container carrying PostScript-outline members instead of TrueType ones. Converting WOFF back to TTF/OTF unlocks fonts trapped in old web projects for desktop install and editing.
Because the whole conversion happens on your device, it is instant, unlimited and genuinely private — no accounts, no watermarks, no files on anyone's server. Multiple files are converted in one go.
How OTC compares to WOFF
| OTC | WOFF | |
|---|---|---|
| Compatibility | Windows, macOS, fonttools | IE9+ and all modern browsers |
| Best for | CJK system font distribution | Legacy-browser web fonts |
How to convert OTC to WOFF
- 1
Select your files
Drag & drop your OTC files onto the area above, or click to browse. You can add multiple files at once for batch conversion.
- 2
Convert instantly
Click "Convert to WOFF". The conversion runs entirely inside your browser using WebAssembly — no upload, no queue, no waiting.
- 3
Download results
Download each converted WOFF file individually, or grab everything at once as a ZIP archive.
About the OTC format
TTC (TrueType Collection) is how you ship five CJK fonts in one download: a small ttcf header with member offsets points into shared glyph tables, so the fonts that differ only in metrics cost almost nothing extra. Microsoft's SimSun family and macOS system fonts are TTCs.
Most font tools want a single font, not a collection — extraction picks the first member and trims it to its own table directory, producing an ordinary TTF that every converter and @font-face rule accepts.
+Strengths
- ✓Shared glyphs make multi-font files small
- ✓Standard on Windows and macOS for CJK
- ✓First member extracts to a clean TTF
!Limitations
- −Most apps cannot use a collection directly
- −Web @font-face does not accept TTC
- −Members share glyphs — editing one is tricky
About the WOFF format
WOFF (Web Open Font Format, 2010) wrapped TTF/OTF data in a web-first container: zlib compression (~40% smaller), strict table structure, and optional license metadata that foundries required before allowing web embedding. It powered the first generation of real web typography under @font-face.
Its successor WOFF2 compresses better with Brotli and has since become the only format modern sites ship. WOFF remains useful for one reason: legacy browsers (IE9–IE11 era) that never learned WOFF2.
+Strengths
- ✓Compressed and web-legal by design
- ✓Works back to IE9-era browsers
!Limitations
- −Superseded by WOFF2 everywhere current
- −Larger than WOFF2 for identical glyphs
Why convert OTC to WOFF?
Think of it as moving your file to the container that fits the job. Most apps cannot use a collection directly WOFF works differently: Compressed and web-legal by design If any of that sounds like your task, run the conversion — it takes seconds and nothing leaves your device.
Frequently asked questions
Is this OTC to WOFF converter really free?
Yes — completely free, with no sign-up, no watermark and no daily conversion limits. The site is supported by advertising.
Are my files uploaded to a server?
No. The conversion runs entirely inside your browser using WebAssembly, so your files never leave your device — that is what makes it instant and private.
Does it work on Windows, Mac, iPhone and Android?
Yes. Anything with a modern browser works: Windows, macOS, Linux, Android and iOS. No software installation is required.
Is there a file size limit for OTC to WOFF?
The only limit is your device's memory, since nothing is uploaded. Files up to a few hundred megabytes work fine on a modern desktop browser; very large files simply take a little longer.
Do I still need the license for the converted font?
Yes. Converting a format does not change its license — the same foundry terms apply wherever the font is used, including the web.
Does converting OTC to WOFF change how the font looks?
No. The glyph outlines are carried over as they are — conversion changes the container and compression, not the shapes your users see.