The difference between onBlur vs onChange for React text inputs
Tags: react, abotwrotethis
Published: 2023-04-09 01:28:02

If you are a React developer, you may have come across two event handlers that are commonly used for handling input from text inputs - `onBlur` and `onChange`.

While both of these event handlers can be used to handle input changes in React text inputs, there is a significant difference in their behavior and use cases.

In this blog post, we will explore the difference between onBlur vs onChange for React text inputs and when to use each one of them.

## Overview of onBlur and onChange

Before we dive deep into the difference between onBlur and onChange, let's first take a look at what each of these event handlers does.

### onBlur

The `onBlur` event handler is triggered when the text input loses focus. It means that the event will be fired when the user clicks outside the input field or navigates away from it using the Tab key.

### onChange

The `onChange` event handler is fired when the value of the text input is changed. It can be triggered by a wide variety of events, for instance when the user types a character, pastes some text or deletes some existing characters.

## When to Use onBlur?

Now, let's explore the use cases where the onBlur event handler is the most fitting option.

### Form Validation

If you are building a form that requires validation of the input fields, `onBlur` can be a handy event handler to use.

For example, you can use it to verify the validity of the email address entered by the user. When the user types their email, your app will not show any error message until the user moves to the next input field. This behavior provides a seamless user experience.

### Control Over User Navigation

Another useful application of the `onBlur` event is to control the user's navigation.

For instance, if a user completes a text input, you may want to direct them to the next input field. In that case, you can use the `onBlur` event to know when the user has completed filling a particular input field.

## When to Use onChange?

Now that you understand what the `onBlur` event handler is used for let us see when it's appropriate to use the `onChange` event handler.

### Instant Feedback

When you want to provide users with instant feedback on the content they are typing, `onChange` is the right event handler to use.

For instance, as a user types their password, you may want to advise them on the strength of the password. With `onChange`, you can instantly show a progress bar indicating the strength of the password.

### Real-time Search

One of the most common use cases for `onChange` is in a search input field.

When a user types a query to search for something, the results should be shown in real-time as the user types. By using `onChange`, you can fetch data from the backend and show it to the user with every keystroke.

## Best Practices when using onBlur and onChange

Now that you understand the use cases for `onBlur` and `onChange` let's take a look at some best practices to follow when using these event handlers.

### Limit the Number of Event Listeners

Adding too many event listeners can have a significant impact on the performance of your React application.

To prevent this, minimize the number of event listeners in your app by grouping related functionalities into a single event listener.

### Prevent Inconsistent User Experience

Inconsistent user experiences can be frustrating to users.

To prevent this, ensure that the behavior of your onBlur and onChange event handlers is consistent throughout your app.

### Optimize Your Code

Finally, you should optimize the code associated with both event handlers to maximize the performance of your React application.

One way to achieve this is to reduce the size of the bundle by minifying your JavaScript code. Another strategy is to make use of React’s memoization feature to prevent unnecessary re-renders.

## Conclusion

In conclusion, `onBlur` and `onChange` are two event handlers that are commonly used for handling input changes in React text inputs.

While they may seem similar, they have distinct differences in behavior and use cases. By understanding these differences, you can make informed decisions about when to use each of these event handlers in your React application.

When it comes to which event handler to use, remember that `onBlur` is best suited for performing validation and controlling user navigation, while `onChange` is ideal for providing instant feedback and real-time searching.

By following the best practices outlined in this blog post, you can optimize your React application’s performance and provide a consistent user experience.