.FON File Extension

Windows Font Library

Developer Microsoft
3.6  |  29 Votes

What is a FON file?

A FON file is a Windows 3.x font library file referenced by programs that access system fonts. It contains a number of fonts saved in the .FNT file format. FON files are now obsolete.

More Information

FON files are .EXE files that have been renamed to use the .fon extension. Instead of containing an executable program, a FON file contains bitmapped or stroked fonts saved as FNT files. Various programs that use Windows fonts reference the default FON file included with the operating system.

Notably, the fonts contained within a FON file cannot be resized like TrueType (.TTF) fonts. So, you may find several similar yet differently-sized fonts within a FON file. This is one of several reasons why TrueType fonts replaced FON- and FNT-based fonts.

How to open a FON file

You can open a FON file in Microsoft Windows Font Viewer, which is included with Windows. To do so, simply make sure your FON file is located in the directory C:\​Windows\​Fonts and then double-click the file. As long as you have not changed FON files' default file association, your file will open in Font Viewer.

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Programs that open FON files

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