How to use React Developer Tools

React Developer Tools, simplifies the process of debugging and optimizing React code. As a popular JavaScript library for building user interfaces, React has gained immense popularity among developers worldwide. However, debugging and optimizing React code be a challenge.

With React devtools extension, developers can easily inspect and manipulate the state and props of components, analyze component hierarchies, and track component updates in real-time. In this blog, we will go through the features of React devtools extension, steps to set it up, and share how can you use it with examples.

Let’s get started.

What is React Dev Tools extension?

React dev tools is a browser extension meant to assist developers in debugging and optimizing React applications. It shows developers a visual depiction of the component hierarchy, properties, and state of each component in the application.

With this extension, developers can inspect and manipulate the components and their state in real-time. They can also identify performance issues in the application with its built-in profiler.

Why Should You Use the React Dev Tools Extension?

Whether you're new to the world of web development or an experienced programmer, the React Developer Tools extension is a must-have tool in your arsenal. Let's explore how this tool can enhance your development process and why it's essential for anyone working with React.

1. Effortless Debugging

React Developer Tools offers a comprehensive and user-friendly debugging experience that can significantly ease the development process. This extension allows you to:

• Inspect component hierarchy: Easily view the tree structure of your React components.
• Modify props and state: Instantly tweak and adjust component properties and states to see how changes affect your application.
• Real-time component updates: Track updates as they happen, giving you immediate feedback on your code's behavior.

This detailed insight into React's inner workings helps developers quickly identify and fix issues, making the debugging process not just faster but also more effective.

2. Optimize Performance

Performance optimization is crucial for creating smooth and responsive applications. React Developer Tools provides:

• Performance analysis tools: Use flame graphs and profiling to analyze rendering times and pinpoint bottlenecks.
• Identification of inefficiencies: Discover components that render too often or update unnecessarily, which can slow down your app.

By leveraging these features, developers can fine-tune their applications, ensuring they run efficiently and deliver a seamless user experience.

3. Simplified Component Testing

Testing components is a breeze with React Developer Tools. This tool enables you to:

• Inspect individual components: Check if components receive the correct data and render as expected.
• Modify props in real-time: Simulate different scenarios and test how components behave under various conditions.

This level of control and visibility simplifies the testing process, ensuring your components function perfectly before they go live.

4. Ease of Product Adoption

Understanding how components interact within your application is vital, especially when onboarding new developers or collaborating with stakeholders. React Developer Tools helps you:

• Analyze component usage: Gain insights into how components are used throughout your app.
• Communicate effectively: Use your understanding of the app’s structure to improve collaboration with team members and stakeholders.

5. Cross-Browser Compatibility

The versatility of React Developer Tools extends to its compatibility with all major browsers, including Google Chrome, Microsoft Edge, Mozilla Firefox, and Safari. This flexibility ensures that you can use this essential tool on your preferred browser without any hassle.

Conclusion

React Developer Tools is not just a handy extension—it's a powerhouse that transforms the React development experience. By integrating this tool into your workflow, you can enjoy faster debugging, performance optimization, easier component testing, better product adoption, and consistent performance across multiple browsers. If you're developing with React, this tool will undoubtedly make your work easier and more efficient.

Features of React Dev Tools extension

Now that you have understood the benefits of using React Developer Tools, it’s a good time we explore some features.

1. Component tree: It is a hierarchical representation of the React component structure in a tree-like format. The tree view displays the parent-child relationships between components, allowing developers to navigate and inspect the component hierarchy. You can expand and collapse individual components to see their child components and view their props and state.
2. Inspect element properties: You can view and edit the props and state of each component directly in React DevTools, without any modification in the source code or running application.  With the help of this property, you can troubleshoot code and check for different scenarios.
3. Time-travel debugging: It allows you to step through the state and props of your components at different points in time to check for debugging issues that occur at the time of animations or transitions.
4. Highlights updates: When you make changes to your React application, React Developer Tools can highlight which components have been updated.
5. Profiling: You can measure and understand how components render and update over time, providing valuable insights into the application's performance characteristics.

How to install React Dev Tools in Chrome

Here’s how you can install and use React Dev Tools extension to your Chrome browser:

• First step is to navigate to Chrome Web Store on Google Chrome. Then, go to the React Dev Tools extension, click "Add to Chrome" option. A pop-up window will appear requesting you to add the extension to Chrome. Now, click on the "Add Extension" button.

• To test the extension, open a page containing a React application and click the "RD" icon in the top right corner of your Chrome window. The developer panel providing information about the React components on the page will display on the right side of the screen. In the performance tab of React Dev Tools, you can view the information about components rendered and analyze it using the profiler.

That's it! React Developer Tools is now installed and ready to use in Chrome. Use the method to use this extension in other browsers as well.

React Dev Tools - Profiler and Component

In React Dev Tools, the profiler and component serve different purposes when it comes to analyzing and understanding your React application. Let’s cover them one by one:

Component

The Components feature offers a graphical view of your application's component hierarchy. It enables you to examine and troubleshoot individual components' state, props, and hooks.

By navigating to the Components tab, you gain access to a tree view presenting all rendered components in your application. When you select a particular component, you can explore its existing props, state, and context values, facilitating the process of debugging and comprehending the flow of data within your components.

For example, here is an image which showcases the component tree of a React app. You can explore the nested components and check if any error is popping off.

Furthermore, the Components tab provides visualization and inspection capabilities for a component's lifecycle, hooks, and the associated virtual DOM structure. This comprehensive view assists in understanding the inner workings and relationships of your components.

Profiler

This extension helps is measuring and analyzing the performance of your React components. You can identify all the rendering bottlenecks and optimize it for better performance.

When using the Profiler, you can wrap specific parts of your component tree with the <Profiler> component from React. It allows you to measure the rendering time and interactions within that portion of the tree. Check out this image for a visual representation of how the Profiler works and provides performance insights.

With the Profiler, you can gain insights into how components are rendering, identify components that are causing performance issues, and optimize your application's rendering performance accordingly.

Here's a table summarizing the capabilities of React devtools Profiler and Components, along with their common use cases:

To summarize - once you have used the Components feature in dev tools to inspect components in your React app and identify their properties, state, data flow, and interactions, you can move to the Profiler feature. With Profiler you can measure and analyze the rendering performance of these components.

How to use React dev tools extension with examples

In this section, let’s cover how to use React Dev Tools to inspect your React app and debug components and performance. We will use relevant examples that you can follow for your app as well.

Inspecting with React Dev Tools

We will share how you can inspect and debug performance with profiler. We will refer to this e-commerce website - https://buy-2-wear.netlify.app/ to share the steps.

To get started, you can press “Ctrl + shift + I” to go to the inspect window. From there you can monitor React Dev Tools easily.

For inspecting with React Dev Tools, you can then navigate to the panel shown below to see the component tree and view the props and state of the selected element.

When you open the “Component” tab it will show you a hierarchy tree for your React components. It also allows you to inspect the rendered DOM elements while hovering over the components.

Now, if we move further in the hierarchical tree view of our App component, you will find the child component called Routes. You can expand the Routes component to see the other component nested inside it. By clicking on the Route.Provider component, you can see its props and state in the panel to the right.

Debugging performance with React Dev Tools extension

Performance debugging is an iterative process, and it's crucial to profile and test your application after each change to ensure you're moving in the right direction.

With the help of "Profiler" tab in this extension, you can measure and analyze the performance of your components. Start profiling by clicking on the "Record" button and interact with your application to capture performance data.

Now, analyze the recorded data, including component render times and call stack, to identify performance bottlenecks. Here’s a profiler tab to locate the renders, re-renders and updates over time.

In the above image, you can clearly examine the structure of the component tree and see how they are nested and composed with each other. For example, App → LocationProvider → NavigationProvider → Router and so on. It shows the render duration and commit timings in the commit information tab on the right side of the screen. The priorities of the components are also listed there.

Additionally, you get a Flamegraph for a visual representation of the call stack and timing information for different components. Using “Profiler” is a good option to identify areas where unnecessary re-renders are occurring or rendering can be optimized.

Debugging components with Dev Tools

Now, it’s time to understand how debugging is done with React dev tools. Let’s take an example of a simple React component which is not rendering properly. In this component the counter variable is incrementing by 1, every time when the setCounter function is called.

    

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// import hooks from React
import React, { useState } from 'react';
// Here, we will create a function named Count
function Count() {
  const [counter, setCounter] = useState(0);
// Now, setCounter to increment by 1
  function click() {
    setCounter(counter + 1);
  }
// Rendering the output on the screen
  return (
    <div>
      <h2>Count: {counter}</h2>
      <button onClick={click}>Increment</button>
    </div>
  );
}

export default Count;

Here, the Count component is used for rendering a button and counting value which gets incremented when the button is clicked. However, when you run the application you will notice that the count value isn't updating properly after you click the button.

Now, open React dev tools in your browser and select the “React” tab to debug this issue. From there, you can find the Count component in the component tree and inspect its props and state. If the state of the Count component isn't updating correctly when the button is clicked then you can modify the state of the component

For example, you could include a breakpoint in the click method and halt code execution when the breakpoint is reached. From there, you can use the console to log additional information, or modify the state of the component to see if that resolves the issue.

    

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function click() {
  debugger;
  setCounter(counter + 1);
}

We've included a debugger statement in this example to pause code execution and observe the state of the component when the click function is called.

There are multiple ways to debug issues with React Dev Tools. Here are some:

• Use the “Hooks” tab to inspect and debug the state and effect hooks used by a component.
• Modify the props or state values to test different scenarios and observe the component’s behavior in real-time.
• Identify any incorrect or unexpected values in the component’s props or state.

Other dev tools for React

Although React Dev Tools is the most common tool for debugging and profiling React apps, there are other devtools as well that support in React development. These dev tools offer additional functionalities for debugging and optimizing your React apps. Here, are some tools worth knowing:

1. Storybook - This open-source tool primarily focuses to document your components and create visual library of your app’s UI elements. Some popular add-ons are docs, actions, knobs, and viewport. Give this dev tool a try and see the ease in building and testing component yourself.
2. Bit - If you want to build, share and reuse React components and other Javascript modules, then Bit is the right option for you to explore. It helps you in keeping track of changes to your components over time.
3. React Styleguidist - You can use this dev tool to create and manage well-documented libraries. It allows us to automatically update style guidelines when the component changes.

There are more such React tools for developers out there, that you can explore to simplify React development, testing, and debugging.

Conclusion

React dev tools compatibility with your favorite browsers and straight forward interface, no doubt makes it so popular. And I believe, by now you must have gained a comprehensive understanding about this extension, and how you can use it for debugging and profiling your React applications. So do give it a shot.

In this blog we have also mentioned some other tools that use for your React app, but this list is long and it won’t hurt to know about them. So before you get busy with coding, check out our blog on popular React dev tools.

Happy Coding!

Read our comprehensive guide on react developer tools for more insights.