How to Dynamically Resize Text in Flutter

Text is an essential part of any mobile application, whether it be a simple label or a full-fledged article.

However, one of the most challenging things while working with text is to ensure that it fits within the constraints of the screen and is easily readable by the user.

In this article, we will discuss how to dynamically resize text in Flutter, ensuring that your text is readable, no matter the screen size.

Understand the Constraints

The first step in dynamically resizing text is to understand the constraints within which the text will be displayed.

This includes the width and height of the container, the font size, and the number of lines the text can occupy.

Once you have a clear understanding of these constraints, you can determine the optimal font size for the text.

The Text Widget

The Text widget in Flutter is the simplest way to display text in your application.

It accepts a string of text, a style, and a few other optional parameters.

The style parameter is where you can specify the font size, color, and other visual properties of the text.

The Text Spans

Text Spans are a useful tool for working with multi-style text in Flutter.

With Text Spans, you can apply different styles to different parts of the text. For example, you can have one part of the text bold and another part italic.

This can be useful when dynamically resizing text because you can use different styles to control the size of the text.

The Text Style

The Text Style is an important property of the Text widget and Text Spans.

It controls the visual appearance of the text, including the font size, color, and other visual properties.

When working with dynamically resizing text, it’s important to understand how the Text Style affects the size of the text.

Calculating the Optimal Font Size

Once you understand the constraints, you can calculate the optimal font size for the text.

There are several ways to do this, including using the MediaQuery.of method to get the size of the screen and calculating the font size based on that.

Another approach is to use the FittedBox widget, which will automatically scale the text to fit within the constraints.


Dynamically resizing text is a crucial aspect of mobile app development and can greatly impact the user experience.

By understanding the constraints and using the right tools, such as the Text widget, Text Spans, and the Text Style, you can easily achieve dynamically resized text in Flutter.

Whether you’re a beginner or an experienced developer, this comprehensive guide will help you take your Flutter skills to the next level.