COMPOSITEFONT File

What are COMPOSITEFONT files and how to open them

Are you having problems opening a COMPOSITEFONT file or are you simply curious about its contents? We're here to explain the properties of these files and provide you with software that can open or handle your COMPOSITEFONT files.

What is a COMPOSITEFONT file?

A .COMPOSITEFONT file is a Windows Composite Font file.

Windows Composite Font files define how Windows Presentation Foundation (WPF) combines multiple regular typefaces into a single virtual font family so that characters from many scripts, languages, and Unicode ranges display properly without missing glyph boxes. These files specify which real font should be used for which Unicode range and under what style, and they also control fallback behavior when a character is not available in the primary font.

Such a font definition is created by Microsoft (or toolkits like Visual Studio) and consumed by WPF via the System.Windows.Media API. Developers author these definitions in XML using a schema identified by the XML namespace "http://schemas.microsoft.com/winfx/2006/xaml/composite-font" so that applications using WPF can construct a FontFamily instance that respects language, Unicode range, weight, style, underlining, and strikethrough settings.

These files do not contain the actual font outlines or glyph data; instead they contain rules mapping particular ranges of Unicode code points and language identifiers to existing installed fonts and specifying style-related attributes like underlining thickness or baseline metrics. One typical use is Windows' global composite fonts such as GlobalSerif.CompositeFont, which map scripts - Armenian, Tibetan, Han characters, etc. - to appropriate font families.

Identification if opening a file: it begins with an optional byte-order mark (UTF-8, EF BB BF) followed by an XML element <FontFamily xmlns="http://schemas.microsoft.com/winfx/2006/xaml/composite-font">. Internal tags include FontFamily.FamilyTypefaces, FamilyNames, FamilyMaps, attributes like UnderlineThickness, StrikethroughPosition, LineSpacing, Bahasa identifiers such as Language="zh-Hans" or Language="zh-Hant", Unicode ranges like "0F00-0FFF", "20000-2A6DF", and font targets like "Microsoft YaHei", "Malgun Gothic", "Plantagenet Cherokee".

How to open COMPOSITEFONT files

Important: Different programs may use files with the COMPOSITEFONT file extension for different purposes, so unless you are sure which format your COMPOSITEFONT file is, you may need to try a few different programs.

We have not yet verified any programs for Windows that work with this specific file format. If you know one, please use the 'Suggest a program' link below. Thanks!

Last updated: September 2, 2026

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