How To Change Flutter Textfield Error Text Size [Detailed Flutter Guide]

In this tutorial, we’ll learn how to properly customize Flutter textfield error text size by using practical Flutter code examples.

Introduction: Flutter Textfield Error Text Size

Flutter textfield error text is the text that is shown in the bottom left side of Flutter textfield underline/outline border.

It is shown whenever a wrong input(implemented through proper logic) is given to the Flutter textfield.

For instance, if the user input some blank space inside the email textfield then we can show a Flutter textfield error text. If you want to learn how to create this logic in Flutter textfield then click here. It will be same for textformfield as well.

In this post, we’ll see how to easily change Flutter textfield error text size. So let’s get right into it.

Default Flutter Textfield Error Text Size

For that, we’ve to use the decoration constructor of Flutter textfield widget and pass it input decoration. Then by using the error text constructor of input decoration, we can easily set error text.

For demonstration, we’ll pass a simple string as this constructor only accepts a string. Let’s now see what the default Flutter textfield error text size is. See below code:

TextField(
         decoration: InputDecoration(
             errorText: 'Default Error Text Size'
             )
              )

Change Flutter Textfield Error Text Size (Multiple Examples)

In order to do that, we’ve to use the error style constructor of input decoration widget. It accepts a text style widget so we’ll pass it a Flutter text style widget. This text style has a fontSize constructor. It accepts a double(decimal) value but passing it an integer value will also work just fine. So for demonstration, we’ll pass some values to it. See below code examples:

Example 1

decoration: InputDecoration(
                  errorText: 'Custom Error Text Size',
                  errorStyle: TextStyle(fontSize: 10))

decoration: InputDecoration(
                  errorText: 'Custom Error Text Size',
                  errorStyle: TextStyle(fontSize: 18))

In the above examples, we can see that Flutter textfield error text size is customized.

So this is how we can easily give an error text a size of our choice. Hope you like this post.

The complete source code of Flutter textfield error text with custom size is given in the next section.

Custom Flutter Textfield Error Text Size Source Code

import 'package:flutter/material.dart';
void main() {
  runApp(const MyApp());
}
class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      home: Homepage(),
    );
  }
}
class Homepage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return SafeArea(
        child: Scaffold(
      body: Center(
          child: Padding(
              padding: EdgeInsets.symmetric(horizontal: 40),
              child: TextField(
                decoration: InputDecoration(
                    errorText: 'Custom Error Text Size',
                    errorStyle: TextStyle(fontSize: 18)),
              ))),
    ));
  }
}

Conclusion

To conclude this tutorial, now you’ve a detailed practical knowledge of how to customize Flutter textfield error text size. I’d love to have your feedback on this post.

I’d also love to see you visit my other tutorials on Flutter app development and Python programming as well. Thank you for reading this post.