OTC is the CFF-flavored OpenType collection — the same ttcf container carrying PostScript-outline members instead of TrueType ones.
Typical use: Extract a member font from an OTC collection exactly like TTC.
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
- Structure
- ttcf header + member offset table + sfnt members
- Types / schema
- Binary container of sfnt fonts
- Compatibility
- Windows, macOS, fonttools
- Best for
- CJK system font distribution
Convert OTC to…
3 direct directions, sorted A–Z; 🔥 marks popular targets.
Frequently asked questions
What is a OTC file?
OTC is the CFF-flavored OpenType collection — the same ttcf container carrying PostScript-outline members instead of TrueType ones.
How do I convert OTC files online?
Pick a target format from the "Convert OTC to…" list below, drop your file and hit convert. Everything runs in your browser — no install, no upload, no watermark, no limits.
Is it safe to convert OTC files here?
Yes. Every conversion is performed by your own device inside the browser — files never leave for a server, and the page keeps working even offline.
Which formats can OTC convert to?
This page lists all 3 directions across documents, images, audio, video, spreadsheets and archives — each one is its own free converter page.