React Devtools is a Chrome browser extension that allows you to debug and inspect React components in the browser devtools. It provides powerful debugging features like component inspection, React profiling, and view component props and state. Installing React Devtools is simple and straightforward if you follow the right steps. In this comprehensive guide, we will walk through everything you need to know to get React Devtools up and running in Chrome.
What is React Devtools?
React Devtools is a debugging tool created by Facebook to help React developers inspect, monitor, and debug React components in the Chrome developer tools. Here are some of the key things it allows you to do:
- Inspect the React component hierarchy – See the parent-child relationship between components
- View props and state – View the props and state of any React component
- See which components re-render – See exactly which components get re-rendered when state changes
- Debug props, state, hooks and more – Use React debugging tools like prop types and fiber inspection
- Filter components – Search for components by name or filter them in the inspector
- Profiling – Measure how long React rendering and diffing takes
In summary, React Devtools makes debugging React apps much faster and easier by giving you insights into your components. It’s an invaluable tool for any React developer.
Why Install React Devtools?
Here are some key reasons why you should install React Devtools:
- Inspect your React component hierarchy – The component inspector lets you visualize the tree-like component structure of your app to understand how components are nested and arranged.
- View props and state in components – You can quickly check the props and state passed into any component to debug issues.
- Confirm UI updates and re-renders – With highlight updates enabled, you can easily see which components re-render when state changes.
- Find performance bottlenecks – The profiler can reveal slow render times that indicate areas to optimize.
- Improve debugging workflow – Devtools provides a central place to debug React issues faster.
In short, React Devtools supercharges your debugging workflow and gives you vital insights into your React apps. The time saved from debugging issues faster is well worth installing it.
Requirements for Installation
Before installing React Devtools, there are a couple requirements to note:
- Google Chrome browser – React Devtools is a Chrome extension, so you need Google Chrome installed to use it. It will not work with other browsers.
- Local React app or website – In order to inspect components, you need to have a React application running locally that you can inspect.
- Chrome extensions enabled – React Devtools is installed as a Chrome extension, so you need to allow Chrome extensions to be installed.
As long as you have Google Chrome installed and a local React project to inspect, you are good to go! React Devtools does not require anything special beyond meeting these requirements.
How to Install React Devtools
Here is a step-by-step guide to installing React Devtools:
- Open Google Chrome if you don’t already have it open.
- Go to the Chrome Web Store at https://chrome.google.com/webstore.
- In the search bar, type “React Developer Tools”.
- The “React Developer Tools” extension should appear as the first result. Click “Add to Chrome”.
- A dialog will appear confirming you want to add this extension. Click “Add extension”.
- That’s it! The extension will be installed. You’ll see a confirmation that it was added to Chrome.
And with those simple steps, React Devtools is installed! It’s ready to use whenever you have a React app running. Next we’ll cover how to actually use React Devtools.
Using React Devtools
Once installed, using React Devtools takes just a couple steps:
- Ensure you have a React app running locally that you want to inspect. This could be a React codebase you are working on locally.
- Open your Chrome browser and navigate to the React app.
- Right click anywhere on the page and click “Inspect”. This will open the Chrome DevTools.
- You will see a new “Components” tab next to the “Elements” and “Console” tabs. Click the “Components” tab.
- This will open the React Devtools panel, where you can now inspect components!
And that’s all you need to start using React Devtools to inspect your components! Here are some things you can do in the React Devtools panel:
- Browse the component tree
- Search for components by name
- View props and state for each component
- See which components re-render with highlight updates
- Use the profiler to measure render times
- Inspect hooks and component stack traces
- Filter components in the inspector
Take some time to explore all the features of the React Devtools component inspector. It’s the perfect way to start debugging and inspecting your React apps.
Key Features
Now that you know how to open the React Devtools panel, let’s explore some of the most useful features and capabilities it provides:
Component inspector
The component inspector shows the React component hierarchy and structure of your app. You can visualize how components are nested and arranged.
Clicking on any component provides details like name, props, state, hooks, and more. This makes inspecting components intuitive.
Viewing props and state
Select any component to view its props and state in the right panel. You can inspect values of props and state for debugging.
State changes will also be highlighted in green to identify components that re-render.
Searching components
You can quickly search for components by name or regex in the search bar. This makes finding specific components easy.
Highlight updates
With highlight updates enabled, any components that re-render due to state changes will flash green. This allows you to isolate rendering performance issues.
React profiling
The profiler measures how long React rendering takes and identifies performance bottlenecks in components.
You can profile why some component updates may be slow.
Component filters
Component filters allow you to hide components you don’t want to see in the inspector. This declutters the tree.
You can filter by name, props, state, hooks and more. Custom filters can also be created.
Tracing updates
The tracer can replay component mounts, updates, and unmounts step-by-step to breakdown when issues occur.
Inspecting hooks
View hook names, state, and details for any functional component using React hooks.
And more…
React Devtools packs a ton more useful debugging features. Truly explore all it has to offer to get the most out of it.
Debugging Examples
Now let’s walk through a few examples of debugging with React Devtools:
Inspecting component props
If a component isn’t rendering correctly, you can inspect its props in React Devtools to debug.
Just find the component in the inspector, and all its props will display in the panel. You can see if the props are passing down correctly.
Identifying unnecessary re-renders
If your app is re-rendering too frequently, turn on highlight updates. Components that re-render will flash green.
You can then identify patterns around which components re-render often so you can optimize them.
Finding slow render times
If your app feels slow, you can profile your components with the profiler.
This will measure render times to identify badly optimized components you can fix.
Inspecting component state
You can quickly inspect component state to check if it is updating properly on user interactions.
The state panel will highlight state changes as they happen to pinpoint issues.
Checking prop types
Prop types defined in a component will appear in the right panel. You can ensure the received props match the declared types.
This allows you to catch bugs related to incorrect prop types.
Tip and Tricks
Here are some useful tips and tricks to maximize the effectiveness of React Devtools:
- Add the React Devtools Chrome extension to your workspace for easy access.
- Try debugging in Incognito mode which disables other extensions.
- Inspect component state across different pages with the browser history support.
- Filter low-level components like HTML/divs to declutter the inspector.
- Search for components by name or regex if they are hard to find.
- Slow down state changes with the sledding option to track effects easier.
- Integrate React Devtools with your IDE/text editor for powerful debugging.
Put these tips into practice to debug React apps faster. The more familiar you become with React Devtools the easier it gets!
Common Issues
Here are solutions to some common issues you may run into with React Devtools:
Devtools not showing up
If the React Devtools panel isn’t appearing, try restarting the Chrome browser. Also check if you have disabled Chrome extensions.
Blank devtools panel
If the devtools panel is blank, make sure you have a React app launched that you are inspecting. An empty panel means no components detected.
Not detecting components
If components are not detected, ensure you only have one instance of React on the page. Also try simplifying code to isolate issues.
Components incorrectly nested
If the inspector shows incorrect nesting, it may be version incompatible. Upgrade React Devtools and React to latest versions.
Errors logging React version
An error noting React version means incompatible versions. Double check your React and ReactDOM versions match Devtools support.
Profiler not working
If profiling results are blank, the React version may be incompatible. Check that your React version matches profiler support.
Conclusion
Installing React Devtools provides a powerful in-browser debugging experience through its component inspector, props/state views, profiler and many other handy features. It seamlessly integrates with your development workflow.
Follow the installation guide covered here to get set up with React Devtools in Chrome. Then utilize the debugger when inspecting components, examining state changes, profiling components and more.
React Devtools will significantly boost your productivity debugging React apps. The insights it provides helps you write optimal React code and build high-performance components.
Start leveraging its capabilities today to take your React skills to the next level!