Building a Real-Time Application Using React Query Library and WebSockets

Anton Ioffe - March 4th 2024 - 10 minutes read

In the rapidly evolving landscape of modern web development, the ability to build engaging, real-time applications is more crucial than ever. This article delves deep into the confluence of React Query and WebSockets, a powerful duo that is redefining the standards for dynamic, live data interactions within web applications. From the foundational understanding of WebSockets’ full-duplex communication to the practical implementation of a chat application and beyond, we’ll journey through integrating state-of-the-art techniques, optimizing performance, and tackling edge cases. Prepare to be guided through a comprehensive exploration that not only equips you with the technical prowess to master real-time web apps but also ignites the imagination for what’s possible in the realm of real-time functionality. Join us as we unravel the secrets to mastering real-time web applications using React Query and WebSockets, setting a new benchmark for immersive web experiences.

Embracing the WebSocket Protocol

WebSockets enable a full-duplex communication channel that persists over a single TCP connection, facilitating real-time data exchange between client and server without the need to open new connections for each message. This is in stark contrast to traditional HTTP polling techniques, where the client must send a request to the server to receive new data, often leading to inefficient use of resources and a laggy user experience. With WebSockets, information can seamlessly flow in both directions as soon as it's available, making it an ideal choice for applications requiring instant data updates, such as live sports scores or financial tickers.

Establishing a WebSocket connection begins with a handshake initiated by the client, which sends a standard HTTP request to the server with an "Upgrade" header indicating the desire to establish a WebSocket connection. If the server supports WebSockets, it responds with an appropriate "101 Switching Protocols" status code, upgrading the connection from HTTP to WebSockets. This handshake is essential for transitioning to a WebSocket connection while utilizing the same underlying TCP/IP connection of the initial HTTP request, promoting efficiency and lower latency.

Once the handshake is successfully completed, the connection remains open, allowing for bidirectional data flow without the need for reestablishing connections. This persistent connection remains until explicitly closed by either the client or the server, providing a stable conduit for real-time data exchange. This model is particularly advantageous as it reduces the overhead and latency associated with traditional HTTP requests, especially in scenarios where frequent updates are necessary.

However, it's important to manage WebSocket connections judiciously, as each open connection consumes resources on both the client and server. Efficient management includes closing connections when no longer needed and implementing heartbeats or similar mechanisms to detect and close orphaned connections, ensuring optimal use of system resources and maintaining application responsiveness.

In sum, the WebSocket protocol offers a powerful alternative to HTTP polling for developing real-time web applications, providing a seamless, efficient, and bidirectional communication channel. By leveraging persistent connections, applications can achieve real-time data exchange with lower latency and overhead, enhancing the user experience in dynamic and interactive applications. This foundational understanding of WebSockets is crucial for developers looking to integrate real-time functionalities into their React applications, setting the stage for more complex interactions and state management in dynamic web environments.

Integrating WebSockets with React Query

When integrating React Query with WebSockets, one begins by understanding the asynchronous nature of WebSocket communications in contrast to traditional RESTful API calls. React Query, primarily geared toward managing and synchronizing asynchronous state in React applications, becomes immensely useful. It facilitates the handling of data fetched over WebSockets, leveraging its caching and automatic data synchronization capabilities. To set this integration in motion, the first step is configuring the React Query's QueryClient, which serves as the backbone for query management, caching, and invalidation within the application.

React Query's role extends beyond just fetching data; it includes updating the client-side cache upon receiving new data through WebSocket connections. This is achieved by utilizing React Query's queryClient.setQueryData() method to update existing query data or queryClient.invalidateQueries() to mark queries as stale, prompting a refetch of data if necessary. This ensures that the UI remains in sync with the server state without manual intervention, enhancing user experience with up-to-date data representations.

A challenge arises in efficiently managing the lifecycle of WebSocket connections alongside the React Query caching mechanism. Developers must ensure that WebSocket connections are established and torn down in alignment with component lifecycle events or application state changes. This can be gracefully handled within React's useEffect hook, initiating a WebSocket connection on component mount and closing it on unmount, thereby conserving resources and preventing memory leaks.

Moreover, React Query offers the flexibility to integrate WebSocket messages into its data fetching strategies, such as background updates and query invalidation. By intercepting WebSocket messages, one can trigger background data updates using the queryClient.prefetchQuery() method or invalidate queries to fetch fresh data. This hybrid approach of combining WebSockets for real-time data push with React Query for data fetching and caching, offers a powerful pattern for building responsive and data-efficient applications.

In summary, leveraging React Query alongside WebSockets empowers developers to efficiently handle real-time data in React applications. By combining WebSocket's real-time capabilities with React Query's sophisticated caching and data synchronization features, applications can achieve reduced latency, enhanced performance, and improved user experience. This harmonious integration requires mindful management of WebSocket connections and adept handling of cache updates, presenting a compelling case for its adoption in modern web development.

Real-World Example: Setting Up a Real-Time Chat Application

To initiate a WebSocket connection in a React application using the useEffect hook, begin by creating a new WebSocket instance upon the component's first mount. This involves specifying your WebSocket server's URL (wss:// in the WebSocket constructor. It's crucial to handle the onopen, onmessage, and onclose events to manage the connection's lifecycle effectively. For a real-time chat application, managing the opening and closing of the connection is straightforward: set up the connection in useEffect and close it when the component unmounts to prevent memory leaks.

const [message, setMessage] = useState('');
useEffect(() => {
    const websocket = new WebSocket('wss://');
    websocket.onopen = () => console.log('WebSocket Connected');
    websocket.onmessage = (event) => {
        const incomingMessage = JSON.parse(;
        // Handle incoming message
    websocket.onclose = () => console.log('WebSocket Disconnected');
    return () => websocket.close();
}, []);

Integrating WebSockets with React Query involves using the useMutation hook for sending messages and the useQuery or useQueryClient for receiving and optimally managing the messages. When sending a message, useMutation can be used to update the server-side state through the WebSocket connection. Meanwhile, received messages can update the local state directly or invalidate existing queries to refetch the latest data, ensuring the UI is synchronized with the latest server state.

const sendMessage = useMutation(newMessage => {

const { data: messages, refetch } = useQuery('messages', fetchMessages);

websocket.onmessage = () => {
    // Option 1: Direct state update
    // setMessage([...messages, incomingMessage]);

    // Option 2: Invalidate and refetch

While building a real-time chat application, it’s vital to consider edge cases such as attempting to send a message when the WebSocket connection is temporarily down. Implementing reconnection logic or queuing messages to send them once the connection is re-established can enhance the robustness of your application. Also, consider the user experience by disabling UI elements that require an active WebSocket connection when the connection is not available.

To efficiently handle messages, especially in heavily trafficked applications, employing an event-based subscription model can be beneficial. This model involves the server sending specific event types with the data payload, which the client can listen for and handle accordingly. This approach can simplify the client-side logic, particularly for complex applications with multiple message types or operations.

websocket.onmessage = (event) => {
    const { type, data } = JSON.parse(;
    switch (type) {
        case 'NEW_MESSAGE':
            // Handle new message
        case 'USER_JOINED':
            // Handle new user joining
        // Add more cases as needed

This guide offers a foundation for building real-time applications with React Query and WebSockets, focusing on practical implementation details and best practices. Thought-provoking questions to consider include: How can you scale this pattern for larger applications with more complex data synchronization needs? What strategies can you employ to handle temporary network interruptions gracefully? Reflecting on these questions can help you evaluate the robustness and scalability of your real-time application solutions.

Optimizing Performance and Handling Edge Cases

To ensure that applications utilizing React Query and WebSockets maintain high performance, developers must focus on minimizing unnecessary re-renders. This can be achieved through judicious use of React's React.memo, useCallback, and useMemo hooks. These tools allow components to only re-render when the data they depend on has changed, rather than on every WebSocket message. This strategy is particularly crucial in data-heavy, real-time applications, where WebSocket messages can be frequent and data-intensive.

Managing WebSocket connections effectively is another key area. Developers should ensure that WebSocket connections are only opened when necessary and closed when not in use to prevent memory leaks and ensure efficient use of resources. Implementing reconnection strategies is also important, as network disruptions are inevitable. A robust reconnection strategy could involve exponential backoff mechanisms to prevent flooding the server with reconnection attempts.

Updating the React Query cache in response to WebSocket events requires a nuanced approach. When a WebSocket message indicates that data has changed, the React Query cache should be updated accordingly using methods like queryClient.setQueryData() for immediate cache updates or queryClient.invalidateQueries() to trigger a refetch. This ensures that the UI remains in sync with the server state without unnecessary queries, striking a balance between consistency and performance.

Common pitfalls in integrating React Query and WebSockets include memory leaks and inefficient handling of network disruptions. Memory leaks can occur if WebSocket connections are not properly closed when components unmount or when event listeners are not cleaned up. To mitigate this, ensure that WebSocket cleanup is performed within the useEffect return function. Handling network disruptions gracefully involves implementing strategies to queue outgoing messages that could not be sent and resume normal operation once the connection is restored.

Finally, developers should be mindful of the impacts of high-frequency message updates on application performance. Throttling or debouncing updates can be an effective strategy to prevent overwhelming both the server and the client. For example, in applications displaying real-time analytics data, it might be more practical to update the UI at defined intervals rather than attempting to render every single data update in real-time. This balances the need for up-to-date information with the need to maintain a responsive and performant user experience.

Beyond Chat: Expanding Real-Time Functionality in Web Applications

Web applications are evolving rapidly, pushing the boundaries of real-time interaction beyond simple chat functionalities. With the combined prowess of React Query and WebSockets, developers can now architect applications that offer live notifications, real-time analytics, collaborative editing features, and streaming data, bringing an unprecedented real-time experience to users. These applications require careful consideration of architectural design, focusing on scalability to accommodate a growing number of users and the volume of data exchanged, and security to protect sensitive information transmitted in real-time.

Live notifications are a staple in social media platforms, informing users of new messages, interactions, or updates without the need to refresh the page. Implementing such a feature with React Query and WebSockets involves sending notifications from the server to the client in real time, ensuring that the user interface reflects these updates immediately. This real-time feedback loop enhances user engagement, keeping the application interactive and responsive to user actions.

Real-time analytics dashboards are essential in monitoring applications, providing instant insights into data trends, system health, or user behavior. By tapping into the stream of data flowing through WebSockets, developers can leverage React Query to manage the state of this data on the client side. This enables the construction of dynamic dashboards that update continuously, offering businesses the ability to react promptly to changes in data.

Collaborative editing applications represent another dimension of real-time web applications, where multiple users interact with the same document simultaneously. Here, the challenge lies in synchronizing the document state across all clients, ensuring consistency while minimizing latency. By using WebSockets for real-time communication and React Query for state management and synchronization, developers can create a smooth and cohesive collaborative experience.

Streaming data, especially in financial markets or social media feeds, demands a robust real-time solution to push updates to users as they occur. Integrating React Query with WebSockets allows for efficient data fetching and state management, enabling applications to stream data seamlessly to the end-user. This not only improves the user experience by providing up-to-the-minute information but also reduces the load on servers by minimizing the need for frequent polling.

In conclusion, the fusion of React Query and WebSockets opens up a realm of possibilities for developing innovative real-time web applications. By carefully considering architectural, scalability, and security implications, developers can leverage these technologies to create applications that not only meet but exceed user expectations for real-time interactivity and performance. Through creative thinking and technical expertise, the development of feature-rich, real-time applications is not just possible but within reach, challenging developers to explore the full potential of modern web development technologies.


In this article about building a real-time application using React Query Library and WebSockets, the author explores the benefits of using WebSockets for real-time data exchange and how to integrate them with React Query. The article provides insights into the WebSocket protocol, the process of establishing a connection, and managing connections effectively. It also covers practical implementation details, such as setting up a real-time chat application, optimizing performance, and handling edge cases. The key takeaways include understanding the advantages of using WebSockets for real-time applications, leveraging React Query for data synchronization, and considering scalability and performance optimization techniques. The challenging technical task for the reader is to explore and implement strategies for handling temporary network interruptions gracefully in a real-time application.

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