How to use FontForge to remove unused glyphs and optimize fonts

FontForge is a free font editor that can also be useful for web performance work. If you only need a small set of characters, you can use it to remove unused glyphs, reduce font file size, and export lighter web fonts. This tutorial walks through how to do that step by step, so you can keep the characters you need and ship smaller WOFF2 files.

How to remove unused glyphs with FontForge

Fonts often contain hundreds or even thousands of characters that a website never uses. Those extra glyphs increase font file size and slow down page loading. With FontForge, a free open-source font editor, you can remove unnecessary glyphs and significantly reduce the size of your font files.

In this FontForge tutorial, you'll learn how to remove unused glyphs and export a lightweight WOFF2 web font. For this example, we’ll optimize Inter Regular, originally 302 KB. After removing unused characters, the final file size drops to around 10 KB, nearly 30× smaller. Removing unused glyphs is one of the simplest ways to optimize font file size for websites and improve page speed.

What is FontForge?

FontForge is a free, open-source font editor used to modify and optimize font files. It allows you to:

• edit glyphs and characters
• remove unused glyphs
• convert font formats
• generate web-optimized fonts like WOFF2
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Designers and developers often use FontForge to edit existing fonts and reduce font file size by removing characters their website doesn’t need. 

How FontForge works

FontForge works by giving you full control over the glyphs inside a font file. Each character in a font (letters, numbers, punctuation, and symbols) is stored as an individual glyph. Using FontForge, you can edit those glyphs, remove the ones you don’t need, and generate a new optimized font file.

This makes FontForge useful for tasks like:

• editing existing font files
• removing unused glyphs
• converting fonts to WOFF or WOFF2
• optimizing fonts for websites
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In this tutorial, we’ll focus on removing unused glyphs to reduce font file size and improve website performance.

Why remove unused glyphs from fonts?

Most fonts include character sets for multiple languages. For example, a typical font file may contain:

• Latin alphabet
• Cyrillic
• Greek
• extended punctuation
• special symbols
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If your website only uses the English alphabet, most of those glyphs are unnecessary. Removing unused glyphs is one of the simplest ways to optimize font file size and improve website performance. This becomes especially useful when you are:

• optimizing fonts for websites
• improving page speed
• reducing bandwidth usage
• loading multiple font weights or font families
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Even a few optimized fonts can save hundreds of kilobytes across a website. Removing unused glyphs reduces font file size and helps optimize page speed, especially on marketing websites that load multiple fonts.

Font optimization for websites

Font optimization is an important part of website performance. Large font files increase page weight and can slow down loading times, especially when a website loads multiple font families or weights.

One of the most effective ways to optimize font file size is removing unused glyphs. Many fonts include characters for dozens of languages, even if a website only needs a small subset.

Tools like FontForge allow you to edit the font file, remove unnecessary glyphs, and export a lightweight WOFF2 font that loads faster in the browser. For performance-focused websites, optimizing fonts is a simple way to reduce page weight and improve loading speed.

How to remove unused glyphs in FontForge

To remove unused glyphs in FontForge, import your font file, select the characters you want to keep, invert the selection, then remove the remaining glyphs using Encoding → Detach & Remove Glyphs before exporting the optimized font. Follow these steps to remove unused glyphs in FontForge and optimize your font file size for the web.

1. Download FontForge

Download FontForge from the official website. Install the application and launch it.

2. Import the Font File

Open FontForge and import the font you want to optimize. For this example we use:

Inter-Regular (302 KB)

Once the font is loaded, FontForge will display all glyphs included in the font file.

3. Select the Glyphs You Want to Keep

Drag the mouse to select the characters your website actually uses.

For example:

• A–Z
• a–z
• numbers
• punctuation
• space character
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In our case we selected the English alphabet and space.

4. Invert the Selection

Now we need to select all glyphs we don’t want to keep. Go to:

Edit → Select → Invert Selection

FontForge will now highlight all unused glyphs in the font file.

5. Remove the Unused Glyphs

Delete the selected glyphs. Go to:

Encoding → Detach & Remove Glyphs

This removes all unnecessary characters from the font file and keeps only the glyphs your website actually needs.

6. Export an Optimized Web Font

Now generate the optimized font file. Go to:

File → Generate Fonts

Choose the format:

WOFF2

WOFF2 is currently the best format for web fonts, offering excellent compression and strong browser support.  During export you may see warnings (for example about em-size). In most cases these can be ignored. Your font now contains only the glyphs you selected, which significantly reduces font file size and improves page speed.

Results: how much file size can you save?

Original font size: 302 KB

Optimized font size: ~10 KB

That’s roughly 30× smaller. By removing unused glyphs, you dramatically reduce the font file size without affecting how the font looks on your website. If your website loads multiple font weights or font families, optimizing glyph sets like this can reduce total page weight by hundreds of kilobytes, sometimes even megabytes. For performance-focused websites, that’s an easy win.

When should you optimize fonts?

Font optimization makes the most sense when:

• Your website loads multiple font weights
• performance and page speed matter
• you want faster page load times
• you want to reduce bandwidth usage
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Many websites unknowingly load large fonts containing glyphs for languages they never use. Removing those unused characters is one of the simplest ways to optimize font file size and improve performance.

Final thoughts

Font files often contain far more glyphs than a website actually needs.By removing unused characters with FontForge, you can significantly reduce font file size and generate lightweight WOFF2 web fonts that load faster and improve overall website performance.

Even small font optimizations can noticeably improve page speed, especially on websites that use multiple font families or weights.