How can you avoid common pitfalls when using custom fonts on mobile?

1 Choose the right fonts

Not all fonts are suitable for mobile devices. Some fonts may look great on desktop or print, but they may be too small, complex, or inconsistent for mobile screens. To avoid this pitfall, you need to choose fonts that are legible, scalable, and compatible with different screen sizes, resolutions, and orientations. You also need to consider the language and culture of your target audience, and avoid fonts that may cause confusion, offense, or misinterpretation.

2 Optimize the font files

Custom fonts can add extra weight and loading time to your app, which can affect your app's performance and user experience. To avoid this pitfall, you need to optimize the font files by reducing their size, format, and number. You can use tools like Font Squirrel or Google Fonts to compress and convert your font files to web-friendly formats like WOFF or WOFF2. You can also use font subsetting to remove unnecessary characters and glyphs from your font files, and only include the ones that you need for your app.

3 Use fallback fonts

Sometimes, custom fonts may not load or display correctly on some devices or browsers, due to network issues, compatibility problems, or user preferences. To avoid this pitfall, you need to use fallback fonts that can substitute your custom fonts in case they fail. Fallback fonts are standard fonts that are widely available and supported on most platforms and devices. You can use CSS font-family property to specify a list of fallback fonts in order of preference, and use generic font families like serif, sans-serif, or monospace as the last resort.

4 Test your fonts

Even if you choose, optimize, and fallback your custom fonts carefully, you still need to test them on different devices, browsers, and scenarios to ensure that they work as intended. To avoid this pitfall, you need to test your fonts on various screen sizes, resolutions, orientations, and zoom levels, and check for any issues with legibility, alignment, spacing, or contrast. You also need to test your fonts on different network conditions, such as offline, slow, or unstable, and see how they load and display. You can use tools like BrowserStack or Device Mode to simulate different devices and browsers.

5 Follow accessibility guidelines

Custom fonts can be beneficial for your app, but they can also affect accessibility for users with visual impairments or disabilities. To avoid this, you should adhere to accessibility guidelines and best practices. This includes using sufficient font size and line height for readability and comfort, adequate color contrast between text and background for visibility and distinction, clear and simple font styles that are easy to read, appropriate font weight and emphasis to convey hierarchy and importance, as well as alternative text or captions for images or icons that use custom fonts. If you keep these tips in mind, you can use custom fonts on mobile without compromising performance, accessibility, or compatibility. Custom fonts can improve the aesthetics, branding, and readability of your app; however, they require careful planning, optimization, and testing to avoid any issues.

6 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?