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FontCreator Tutorials

Subsetting Fonts by Reducing the Character Set

written by Erwin Denissen, published September 17, 2024

Introduction

Subsetting a font is a valuable technique for optimizing performance by reducing file size. This can be done by limiting the character set to only the glyphs you need, whether you're working with regular or variable fonts. Removing unused or unnecessary characters helps streamline your font, resulting in a smaller file that loads faster and performs better—especially for web use.

Although FontCreator doesn't have a dedicated feature specifically for reducing the character set, it allows users to easily include or exclude glyphs during the export process. In this article, we'll show you how to manually subset a font's character set using FontCreator, whether you're working with a regular or variable font.

Note: We will not cover how to subset a variable font by excluding axes or adjusting their ranges in this article. For more information on this topic, please see:

Subsetting Variable Fonts with FontCreator


Why Subset the Character Set?

  1. File Size Reduction
    Fonts often contain thousands of glyphs, including characters for multiple languages, symbols, and punctuation marks. By subsetting the font and removing unnecessary glyphs, you can significantly reduce its file size, making it faster to load and easier to handle in various applications.

  2. Optimized Web Performance
    A smaller font file means quicker load times, an essential aspect of optimizing websites and apps. Subsetting your font to only include the necessary characters ensures that it loads faster, improving the overall user experience.

  3. Tailored Character Usage
    Subsetting is especially useful if your project only requires a limited number of characters—whether it's for a specific language, brand design, or a particular set of symbols. You can customize the font to include only the characters you need, keeping the file lean and efficient.


How to Subset the Character Set in FontCreator

FontCreator makes it easy to manually subset a font’s character set, allowing you to select which glyphs to include or exclude during export. Here’s how you can achieve this for both regular and variable fonts:

Step 1: Open the Font in FontCreator

Start by opening your font in FontCreator. This loads the entire glyph set into the editor, where you can view and modify the characters as needed.

Step 2: Deselect All Glyphs

From the font overview window, select all glyphs by pressing Ctrl + A or using the selection tools. Right-click on the selection and choose Include in Exports -> None. This marks all glyphs as not exported.

Step 3: Select Unmapped Glyphs

Navigate to the left categories treeview and select Glyphs -> Unmapped. Select all glyphs, right-click, and choose Include in Exports -> All Exports. This action ensures that all OpenType layout features relying on the included characters remain functional. Additionally, make sure to set the option to exclude all unused glyphs in the Options dialog's Font page.

Step 4: Select Desired Unicode Categories

Navigate to the left categories treeview and select a Unicode category you want to include, such as Basic Latin. Highlight all glyphs within this category, right-click, and choose Include in Exports -> All Exports. Repeat this process for any other Unicode blocks you wish to include.

Step 5: Select Additional Glyphs to Keep or Remove

If needed, manually select additional glyphs you want to include or exclude from the export. This manual selection process gives you complete control over which characters will be present in the final font, regardless of whether it’s a regular or variable font.

    Step 6: Export the Subsetted Font

    Once you’ve finalized your glyph selection, go to the Export Settings window and proceed to export your font. The resulting file will include only the glyphs you chose, ensuring a smaller, more efficient font tailored to your project’s specific needs.


    Conclusion

    Subsetting a font by reducing its character set is a powerful way to optimize performance, whether you’re working with a regular or variable font. While FontCreator doesn’t have a dedicated character set reduction tool, its intuitive manual selection process makes it easy to include or exclude glyphs during export. This allows you to remove unnecessary characters and reduce file size, improving load times and making your font more manageable.

    Whether you're designing for the web, mobile apps, or specific branding projects, subsetting your font ensures that you only include the characters you need, resulting in a more streamlined and efficient font file.