Free online OTC to TTF converter

What the OTC format is

OTC is an OpenType Collection. It is an sfnt container that stores multiple related OpenType fonts in one file while sharing identical tables such as glyph data, character maps, metrics, or naming information. Font vendors and font-production tools use it to package families or regional variants efficiently; operating-system font packages are a common place to encounter one.

An OTC can contain fonts with either TrueType outlines in a glyf table or CFF/CFF2 outlines in a CFF or CFF2 table. The .otc extension therefore does not identify one specific outline technology, and conversion normally requires selecting one face from the collection.

What the TTF format is

TTF conventionally means a standalone TrueType-flavored font containing quadratic outlines in a glyf table. It is supported by Windows, macOS, Linux, design applications, office software, and many embedded systems. A standalone file is easier to install and reference than a collection when software cannot read OTC containers.

TTF is not simply another name for every OpenType font. An OpenType font with CFF outlines can use an .otf filename, while a file intended as TTF must normally contain TrueType outlines. Changing the extension does not perform this conversion.

How to actually convert OTC to TTF

Using FontForge

1. Install the desktop version of FontForge and open family.otc through File → Open.
2. If FontForge displays a face-selection dialog, choose the family member and style to export. Repeat the process for every face you need; one OTC can produce several TTF files.
3. Choose File → Generate Fonts.
4. Select TrueType as the output format, enter a filename ending in .ttf, and generate the font.
5. Install the generated file temporarily and test its glyph coverage, accented characters, spacing, hinting, and behavior in the target application.

FontForge is the practical choice when an OTC member uses CFF or CFF2 outlines, because it can convert the outlines to quadratic TrueType curves during generation. Review the generated font rather than assuming that the conversion preserved every original feature.

Extracting members that already use TrueType outlines

If the collection members already contain glyf tables, FontTools can extract them without redrawing the outlines. Install it with pip install fonttools, save the following as extract_otc.py, and run python extract_otc.py:

from fontTools.ttLib import TTCollection

collection = TTCollection("family.otc")
for index, font in enumerate(collection.fonts):
    if "glyf" not in font:
        raise RuntimeError(f"Member {index} is not TrueType-flavored")
    font.flavor = None
    font.save(f"family-{index}.ttf")

This produces one standalone TTF per collection member. The script deliberately stops for CFF/CFF2 members because merely saving them with a .ttf suffix would not convert their outline format.

For a no-install option, the conversion can also be performed for free on 101convert.com by uploading the OTC file and selecting TTF as the output format.

Quality, compatibility, and limitations

A CFF-to-TrueType conversion changes cubic Bézier outlines into quadratic curves and may alter hinting, file size, rasterization, or spacing. Inspect small text sizes on the operating systems where the font will be used.

Collections may contain variable-font axes, color glyphs, OpenType layout tables, or licensing restrictions. FontForge may not preserve every variable or color-font feature when generating a conventional TTF, and some applications still cannot use advanced tables after conversion. Retain the original OTC as the archival source, confirm the font license permits conversion and redistribution, and use a font editor or FontTools inspection to verify the resulting tables before deployment.