TTC (TrueType Collection)
One file, many fonts: TTC packs multiple typefaces together so systems can share glyph tables and cut storage in half.
| Full name | TrueType Collection |
| Extension | .ttc |
| MIME type | font/collection |
| Developer | Apple and Microsoft |
| Released | Mid-1990s (CJK Windows); broadly adopted with Windows 2000 and Mac OS 8.5) |
| Type | Font collection container |
| Based on | TrueType / OpenType |
| Table sharing | Multiple fonts share identical tables (glyf, cmap, etc.) |
What is a TTC file?
TTC is a font container format that holds multiple TrueType or OpenType fonts inside a single file. Fonts in the collection can share glyph and layout tables, which reduces total file size. It was created to handle large East Asian character sets that span thousands of shared glyphs across font weights.
A TTC file starts with a TTC Header that lists the offset of each font inside the archive. Each font still has its own complete Table Directory, just like a standalone TTF. Tables that are identical across fonts — such as the glyph outlines or the character map — are stored once and referenced by every font that needs them. The result is a smaller file than shipping each weight as a separate TTF.
History
TrueType itself was designed by Apple in the late 1980s and licensed to Microsoft, which shipped it in Windows 3.1 in April 1992. The Collection extension appeared in the mid-1990s to support Chinese, Japanese, and Korean (CJK) versions of Windows, where a single script can require tens of thousands of glyphs shared across multiple weights. Windows 2000 extended TTC support to all regions, and Mac OS 8.5 added native support on the Apple side. The OpenType specification later absorbed the TTC container, keeping the same .ttc extension.
How it works
The file opens with a four-byte tag ('ttcf') that identifies it as a collection, followed by a version number and a count of fonts inside. An array of offsets points to each font's Table Directory. Each Table Directory then points to the actual font tables — glyph data, kerning, character maps, and so on — which may be shared memory addresses across multiple fonts in the same file.
What it is used for
- Shipping a complete type family (Regular, Bold, Italic, Bold Italic) as one download
- Distributing CJK system fonts where thousands of glyphs are shared across weights
- Reducing disk footprint on operating systems that bundle many locale-specific fonts
- Embedding multiple weights in a single font resource inside a PDF or application bundle
How to open it
Modern operating systems — Windows, macOS, and Linux with FreeType — open TTC files automatically; just double-click to preview or install all fonts inside. Font editors such as FontForge, Glyphs, and FontLab can open and extract individual fonts from a TTC file for editing.
Pros and cons
Strengths
- Smaller total file size because shared tables are stored only once
- Single download installs an entire type family at once
- Natively supported on Windows, macOS, and Linux without extra software
- Fully compatible with the OpenType specification, so all OpenType features work inside a TTC
Trade-offs
- Cannot selectively install one weight without installing the whole file on older systems
- Slightly more complex for developers to parse than a single TTF
- Some older applications and PDF workflows expect individual TTF files and ignore the collection structure
- Editing requires a font tool that understands collections; plain text editors are useless
Convert TTC files
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TTC FAQ
What is the difference between a TTF and a TTC file?
A TTF holds exactly one font. A TTC holds two or more fonts in a single file, with shared tables so the combined size is smaller than separate TTF files would be.
Can I extract individual fonts from a TTC file?
Yes. Tools like FontForge and Python's fonttools library can split a TTC into separate TTF or OTF files, one per font inside the collection.
Why do CJK fonts so often use the TTC format?
East Asian scripts contain tens of thousands of characters. The glyph outlines for those characters are identical across weights, so sharing one copy of the glyph table cuts file size significantly compared to repeating it in every weight.
Is a TTC file the same as an OTC file?
They are closely related. OTC (OpenType Collection) uses the same container structure but can include CFF-based (PostScript-flavored) fonts alongside TrueType-flavored ones. TTC traditionally holds TrueType-flavored fonts only, though the OpenType spec now covers both under the same 'ttcf' tag.