October 12, 2024 | Web Development | Mohit Goyal

Optimizing React Performance: Tips And Tricks For Faster Apps

With an added layer of functionality richness, complex web applications call for optimization. Optimizing your server, app, or website brings the best advantage of faster speed. Optimization of apps for high performance offers usable fluidity. Major apps utilize powerful and trendy JavaScript libraries for dynamic user interface building, like React, and several readymade mechanisms are available. Further, with React js hosting solutions, your optimized apps can perform better.

A developer can also opt for something more, like HTML web hosting, to tweak their apps towards higher quality, faster, and more responsive performance. In this insightful read, we will go deeper into some of the key strategies for optimizing React, including practical advice and tips and tricks that can help you build faster and more efficient applications.

What is React?

React is one of the favorite JavaScript libraries used for the construction of user interfaces. It is powerful and efficient in building dynamic web applications. However, as complexity and scale evolve, performance becomes a bottleneck. Optimizing React performance is necessary to ensure that applications are delivered to users in a smooth way, improve web pages' rankings, and ultimately achieve business success.

Need of optimizing React performance

Here's why optimizing React performance is necessary:

Faster applications result in more satisfactory use from users and retain them on your website or app for a longer period. The better response times are, the better your applications will perform.
Optimizing React performance makes your app show up higher in search results and gain greater visibility and traffic. Thus, with optimization, you see improvements in search engine rankings. Search engines, including Google, have begun considering the speed of websites as a ranking factor.
Another notable aspect is the higher conversion ratios. If your apps load at the fastest speed, it is very likely that it will yield a higher conversion rate. Thus, users view their desired results quickly and have a better user experience.
It’s not hard to figure out that if your apps load faster, you’ll get lower bounce rates. Optimization of performance can help in reducing the bounce of an application and getting the users to spend more time with it.
The more your application grows, the more performance means to you. Hence scalability becomes essential. Optimizing React can help your app scale effectively and handle increased traffic without compromising on the user experience.

Optimize React for faster performance: Essential tips and tricks

Use the Production Build

The first tip would be to ensure that you're using a production build of React. It is one of the react optimization techniques for seamless performance rates. The development build includes extra warnings and debugging information. Although development build is useful in development, it can make your application slower in production. Hence, for better performance, use production build. To create a production build, run the build command, which compresses your code and removes unnecessary warnings, ultimately making your app faster and lighter.

Command: npm run build

Avoid Unnecessary Re-renders

One of the common reasons for the React application's slow performance is the use of unnecessary re-renders. For every case of a component re-rendering, React updates the virtual DOM and compares it to the actual DOM, which can be rather time-consuming, especially for large applications. Developers can significantly improve this by avoiding re-renders.

Here’s how you can avoid unnecessary re-renders:

Use shouldComponentUpdate() or React's PureComponent:

The shouldComponentUpdate() method allows you to choose which components you want to manually update. If you use React's PureComponent, it will automatically call shallow comparisons for both state and props to prevent unnecessary renders.

Use React's memo function:

Using React's memo function on functional components with React.memo() to "memoize" the component only re-renders the component when its properties change.

Example:

const MyComponent = React.memo(function MyComponent(props) {

  // component logic

});

Employ the useMemo() and useCallback() Hooks

In functional components, expensive calculations and functions can be very time-consuming when computed on every render. React’s useMemo() and useCallback() hooks can help optimize performance. These hooks enhance the performance by memoizing values and functions.

useMemo(): This hook memoizes a computed value and recaluates only when its dependencies change.

Example:

const computedValue = useMemo(() => expensiveFunction(input), [input]);

useCallback(): This hook returns a memoized version of a callback function, ensuring that it only changes if its dependencies change.

Example:

const handleClick = useCallback(() => {

  // function logic

}, [dependency]);

Lazy Loading Components using React.lazy()

Lazy loading is a wonderful way to optimize for performance. You don't necessarily need to have all of your apps loaded at one time; instead, you can split them into smaller pieces and then load them on demand. React's React.lazy() lets you import a component only when it becomes relevant for rendering. This narrows your initial load as well as enhances your overall performance.

Commonad: const LazyComponent = React.lazy(() => import('./LazyComponent'));

This method can be used in combination with the Suspense component to render fallback content while the component is loading.

Webpack Code Splitting

Code splitting is an optimization technique that allows you to split your application into smaller bundles, thus reducing the amount of JavaScript code that needs to be downloaded at once. Webpack is the default bundler for React applications and has full built-in support for code splitting.

You can import that dynamically like this:

import(/* webpackChunkName: "component" */ './Component');

This will ensure that your application only loads the code needed for the current page, hence minimizing the time taken to load.

Avoid Inline Usage of Functions and Object Literals

If you use inline functions and object literals in JSX, you should be aware that it leads to poor performance as each render recreates them, leading to unnecessary re-renders. The solution here is to avoid or minimise the use of inline usage of functions and object literals.

Start by defining outside of JSX or memoizing using useCallback().

Avoid inline object literals and the event listeners for instances of an element. It is best to make these outside of the render method or memoize them with useMemo().

Example:

const styles = useMemo(() => ({ color: 'blue' }), []);

Optimizing List Rendering with React.Fragment and Virtualization

Rendering a large list has a major impact on performance. This is mainly because rendering everything in the list takes time and slows down the application. React provides tools that will optimize list rendering and allow only the necessary items in the list to be rendered.

Use React.Fragment to remove unnecessary div wrappers that slow down rendering.

Virtualization: Packages like react-window or react-virtualized will help you optimize huge lists so that only visible items are rendered, and therefore it greatly improves performance.

import { FixedSizeList as List } from 'react-window';

<List height={500} itemCount={1000} itemSize={35}>

  {({ index, style }) => <div style={style}>Item {index}</div>}

</List>

Browser DevTools for Performance Profiling

React DevTools and browser DevTools such as Chrome DevTools have fantastic profiling tools. You can use them to identify performance bottlenecks. Use them to measure time taken for your components to render, to note unnecessary re-renders, and improve your code accordingly.

The Profiler tab in React DevTools lets you record performance and view how much time each component is taking to render.

Debounce or Throttle Events

Debounce or throttle event handlers limit how frequently performance-heavy operations like search input or window resizing are called. In other words, debouncing ensures that a function is called only after the end of a certain period of inactivity. It prevents repetitive occurrence of functions over time, thereby improving the performance for faster apps.

Example of debounce:

const handleSearch = useCallback(debounce((event) => {

  // search logic

}, 300), []);

Avoid Deeply Nested Components

Deeply nested components increase the complexity of your application and slow down the rendering. By breaking up large, complex components into smaller, reusable pieces, you will improve the performance and maintainability of your code.

Web hosting provider and performance of your React app

Your web hosting partner is a major determiner of whether or not your React app is fast. A good hosting provider offers key elements that help improve your React performance. Look for the following key elements while choosing a hosting service:

Server Infrastructure: A robust server infrastructure with adequate resources meets the demands of React applications. For your React apps to be faster, you need an industry-recognized web hosting provider, like MilesWeb. They ensure you get all the resources and features with the best infrastructure.
Network Connectivity: Choose a provider that has top-line network connectivity. It helps quick delivery of the app's resources, increasing the performance of your apps.
Caching: A good caching mechanism can store frequently retrieved data in the local cache, thereby greatly reducing the need to fetch that data from the server.
Content Delivery Network (CDN): A CDN serves static content like images, CSS, and JavaScript of your application from multiple servers across various geographies of the world. This server is the closest to your target users, reduces latency, and is beneficial, especially when you serve international audiences.
Security: The hosting environment of your chosen provider should be secured so that your application and its user data are safe at all times. A good hosting provider will, thus, implement robust security measures so that your application does not fall under attacks and remains consistent.

Summary

Optimizing your React app not only offers seamless functionality but also ensures that users have the best experience. The best thing you can do to optimize your React performance is avoid unnecessary re-rendering with the help of a few inbuilt React hooks, like useMemo() and useCallback(). In this detailed blog, we have also included some modern JavaScript techniques, such as lazy loading and code splitting. All these tricks and tips will let your React application be fast and scalable in the long run.

Again, performance optimization is not a fix-and-forget job. You should profile your app regularly and check its analysis report to find new areas of improvement as your application grows.