Install, configure and use fonts in Flutter

This article mainly covers changing the font family, but since it's related to which fonts you should use or are recommended, we'll cover not only that but also how you can implement a font in Flutter.

Choosing and configuring fonts well in Flutter can completely transform how an app feels and is understood. When you work with screens full of text—titles, subtitles, labels, descriptions, buttons—using the same typeface for everything makes everything look "the same," and the user loses visual cues. It's happened to me: on several screens with a lot of content, the lack of font variety made it harder to distinguish what was important and what wasn't. That's why using the right combination of fonts ends up being a key visual aid... and yes, it also makes the app look nicer.

Mobile apps are an art; they have to be visually appealing, and the user must be able to find anything easily. Typography helps with this. You've already learned how to activate PIP mode in Flutter with Android, now let's move on to the next step.

Flutter can work with custom fonts and can apply a custom font to an entire application or to individual widgets. This tutorial will show you how to create an application that uses third-party fonts with the following steps:

• Import the font files.
• Declare the font in pubspec.
• Set a font as the default.
• Use a font in a specific widget.

Fonts play an important role in application design and development, as they are a determining factor in the legibility, aesthetics, and visual identity of a user interface. 

Each font has its own characteristics, such as weight, letter height, and style, which can affect how users interact with the application and how the presented content is perceived. 

In application design, it is important to carefully choose the font that best suits the application's purpose and target audience, ensuring that it is legible and aesthetically pleasing. 

Furthermore, in some cases, it may be necessary to use different fonts for different parts of the application, such as headers, button text, or body text, to improve the overall usability and accessibility of the application.

With this, you'll be able to use fonts like Font Awesome or, even better, Google Fonts, which allow you to download the font files independently to your PC and copy them to your project.

Roboto and San Francisco are the default font families for Android and iOS, respectively. You might have a custom-made font from a designer, or you may have downloaded a font from any other resource like Google Fonts. Either way, you will need to download the font file (.ttf) and import it into your Flutter project.

Why Fonts Matter in Flutter

Typography as a tool for visual hierarchy

Something I learned when designing screens with a lot of text is that typography doesn't just "decorate": it organizes. Changing the font family between titles, labels, and descriptive texts creates very clear visual levels without the need for extra boxes, colors, or icons.

When you combine a more expressive font for a title and a more neutral one for the body, you give the user an immediate visual map.

How the font influences user experience and clarity

People navigate through an app faster when texts are differentiated. Even small changes—a different family, a different weight—help the reading flow. This reduces cognitive load because the user doesn't have to "decipher" what is what.

Using custom fonts in apps makes a huge difference; by varying the fonts between titles, labels, and buttons, testers better understood the screen hierarchy without changing anything else.

The aesthetic role: an app that "looks better"

Sometimes we underestimate the visual impact of good typography. No matter how technical the app is: if the text looks good, everything looks more professional. When I first added custom fonts, the app gained its own personality without touching colors or layout.

With this, the best thing you can do is combine several fonts:

• Title: more expressive font
• Subtitles / labels: a slightly more technical font
• Body text: very legible font

On screens with a lot of content, changing the family between sections improves clarity. I experienced this when I made a details screen with 7 different components: a single font made everything feel "flat."

Custom text fonts of operating systems

The default font on Android is Roboto and on iOS it is .SF UI Display or .SF UI Text; and this is something you must keep in mind when working with fonts.

If you want to use a different font, you will need to add it to your application, which is what we will present in this post.

Your own custom fonts

How to Add Custom Fonts in Flutter Step by Step

Create the assets/fonts folder

• Inside your project, create a folder assets/fonts/.
• Copy your .ttf or .otf files there.

project/
  assets/
    fonts/
      MiFuente-Regular.ttf
      MiFuente-Bold.ttf

1. Add a font to your project.

To add a custom font to your project, right-click on your project folder and go to New > Directory. Call it assets. It should be in the root directory of your project.
Copy and paste your font into the new assets directory. I'm only using a single font in my example, the regular Dancing Script font. I renamed it to dancing_script.ttf.

Add a font to your assets folder.

2. Register the font in pubspec.yaml.

Open your pubspec.yaml file.

Add the font information in the Flutter section. Indentation is mandatory.

flutter:
  uses-material-design: true

  fonts:
    - family: MiFuente
      fonts:
        - asset: assets/fonts/MiFuente-Regular.ttf
        - asset: assets/fonts/MiFuente-Bold.ttf
          weight: 700

• Indentation is critical.
• The family name will be the one you use in the code.
• You can register all variants (100–900).

3. Use the font in your code by specifying fontFamily

Use the widget directly, by name:

Text(
 'Hello world',
 style: TextStyle(
   fontFamily: 'MiFuente-Regular',
 ),
);
Text(
  'Hola mundo',
  style: TextStyle(fontFamily: 'MiFuente'),
)

Finally:

Common Errors (and How to Avoid Them)

• ❌ Forgetting to completely restart the app after adding fonts.
  It happened to me several times: they just wouldn't load until I did a "Stop" + "Run."
• ❌ Using incorrect paths in pubspec.yaml.
• ❌ Lack of indentation.
• ❌ Declaring the same family name for several different fonts.

Whenever I add assets, I find that I need to do a complete stop and restart. Otherwise, I get errors.

Best Practices for Choosing and Organizing Fonts in Flutter Apps

Differentiating titles, subtitles, labels, and buttons

Using a single family for everything makes the interface visually monochromatic. When I combine two families—one for titles and one for the body—the interface breathes, and everything is better understood.

How to achieve clear hierarchies on screens with a lot of text:

• Title → expressive font
• Subtitle → intermediate weight
• Body → neutral font
• Buttons → compact and clear font

On informative screens, changing the typeface prevents the user from "losing sight" of important elements.

Weights, styles, and spacing to improve legibility

Some professional tips:

• Use 400–500 for general text.
• Use 600–700 for titles.
• Don't overuse weight 900.
• Maintain a height between 1.2 and 1.4 for paragraph text.

Recommendations:

• You can add multiple font families in the same way (you will see this later)
• The family determines the font name and must be unique for different font families.
• The asset is the path to the font from the project root.
• The weight property represents the font weight, an integer value from 100 to 900
• The style property specifies whether the font is normal or italic
   Remember that this material is part of my complete Flutter course.

Using fonts in a custom theme:

ThemeData theme = ThemeData(
 fontFamily: 'MiFuente',
 textTheme: TextTheme(
   headlineLarge: TextStyle(fontSize: 32, fontWeight: FontWeight.bold),
   bodyMedium: TextStyle(fontSize: 16),
 ),
);
***
Column(
 crossAxisAlignment: CrossAxisAlignment.start,
 children: [
   Text("Título", style: TextStyle(fontFamily: 'MiFuente')),
   Text("Descripción larga...",
        style: TextStyle(fontFamily: 'FuenteCuerpo')),
 ],
)

FAQ about Using Fonts in Flutter

• Can I use multiple font families in the same app?
  • Yes, and in fact, on many screens with a lot of content, it is a significant improvement for visual clarity.
• Should I restart the app when adding fonts?
  • Yes, always. Not with hot reload: a complete restart.
• What is the best font for a Flutter app?
  • It depends on the style, but for body text, Inter, Roboto, SF Pro, Poppins, or Noto Sans usually work very well.
• Can I use Google Fonts without downloading the files?
  • Yes, with the google_fonts package. But for production, it is usually better to download the TTFs and have them locally.

✔️ Conclusion

Setting up fonts in Flutter is not just a technical step: it's a design decision that impacts the clarity, hierarchy, and aesthetics of your app. Using different typefaces for titles, subtitles, labels, and descriptions helps guide the user, and on screens with a lot of text, the difference is enormous—I've seen it in my own projects. And the best part: Flutter makes it very easy if you declare your fonts correctly in pubspec.yaml.

The next step is to learn how to use design patterns, specifically the Singleton pattern in Flutter.