Best Practices for Optimizing Web Fonts

Web fonts play a crucial role in the look and feel of a website. However, using web fonts without proper optimization can significantly slow down your website, affecting performance and user experience. Optimizing web fonts not only improves load times but also ensures that your website remains visually appealing across different devices and browsers.

In this article, we’ll explore the best practices for optimizing web fonts, helping you balance aesthetics with performance.

1. Choose the Right Font Formats

When incorporating web fonts, it’s important to provide the appropriate formats for various browsers and devices. Some common web font formats include:

• WOFF (Web Open Font Format): A compressed format with broad browser support, ideal for web usage.
• WOFF2: A more advanced and compressed version of WOFF, offering better performance for modern browsers.
• TTF (TrueType Font): Supported by older browsers but less optimized than WOFF.
• EOT (Embedded OpenType): Mainly used for Internet Explorer, but becoming less relevant.

For optimal performance, prioritize using WOFF and WOFF2 formats in your font loading strategy, while providing fallback options for older browsers.

2. Limit the Number of Fonts and Variants

Using too many different fonts or font weights can dramatically increase page load time. Limit the number of web fonts to 2-3 and reduce the number of font weights or styles (e.g., regular, bold, italic) to minimize HTTP requests and the size of font files.

Example:

Instead of loading:

• Roboto-Regular
• Roboto-Bold
• Roboto-Italic

Consider using just:

• Roboto-Regular
• Roboto-Bold

This reduces the number of files the browser needs to download, improving performance.

3. Use Font Subsetting

Font subsetting allows you to only load the characters you actually need from a font, significantly reducing file sizes. For instance, if you are only using Latin characters, you can subset out characters in other languages, like Cyrillic or Chinese.

Steps to subset fonts:

1. Use tools like Google Fonts, Font Squirrel, or Transfonter to create subsets of the font.
2. Specify the subset in the @font-face declaration.

@font-face {
    font-family: 'Roboto';
    src: url('roboto-latin.woff2') format('woff2');
    unicode-range: U+000-5FF; /* Latin characters only */
}

By limiting the font file to the necessary character sets, you can significantly improve load times.

4. Implement Font Loading Strategies

Different font loading strategies can help balance the appearance of your website while improving performance. There are three main strategies to consider:

• FOIT (Flash of Invisible Text): Text remains invisible until the font is fully loaded. This ensures a consistent look but can cause a delay in rendering text.
• FOUT (Flash of Unstyled Text): The browser displays a fallback font while the web font loads, then switches to the desired font. This is better for performance but may cause a shift in layout.
• Font-display: swap: This CSS property allows for a fallback font to be shown immediately and swaps it with the web font once it’s loaded. This is a balanced approach between FOIT and FOUT.

@font-face {
    font-family: 'Roboto';
    src: url('roboto.woff2') format('woff2');
    font-display: swap;
}

Using font-display: swap ensures your text remains visible while the font is being loaded, improving user experience.

5. Preload Key Fonts

Preloading fonts can ensure that critical web fonts are fetched early during the page load process, avoiding delays in rendering. Use the <link rel="preload"> tag to preload your most important fonts.

<link rel="preload" href="/fonts/roboto.woff2" as="font" type="font/woff2" crossorigin="anonymous">

This tells the browser to prioritize fetching the font file, ensuring faster rendering of your website’s text content.

6. Use System Fonts as Fallbacks

To minimize the impact of web font loading, always specify a system font as a fallback in your font-family declaration. System fonts are already installed on users’ devices, so they load instantly.

Example:

body {
    font-family: 'Roboto', Arial, sans-serif;
}

In this case, the browser will load Arial (a system font) if Roboto isn’t available or hasn’t loaded yet, ensuring the text is still displayed quickly.

7. Compress and Cache Font Files

Ensure that your font files are compressed and stored efficiently on your server. Use modern compression techniques such as Gzip or Brotli to reduce the size of font files and improve download times.

Additionally, configure your server to cache fonts so that returning users don’t need to re-download them. Set appropriate cache headers to store font files in users’ browsers for an extended period.

Cache-Control: public, max-age=31536000, immutable

This ensures that font files are cached for one year, preventing unnecessary re-downloads and improving load times for repeat visitors.

8. Optimize Font Delivery Using a CDN

Using a Content Delivery Network (CDN) can further enhance font loading speeds by serving font files from locations closest to your users. Many web fonts are hosted on CDNs, such as Google Fonts or Adobe Fonts, which can automatically distribute font files to users from the nearest server.

Conclusion

Optimizing web fonts is an essential part of improving website performance. By following these best practices—choosing the right formats, limiting font variants, subsetting, using font-loading strategies, preloading key fonts, and more—you can ensure your fonts load quickly and smoothly.

For expert help with web performance and font optimization, TechsterTech specializes in building fast, efficient websites that don’t compromise on design or user experience. Reach out to us today to enhance your website’s performance!