When building real-time features with Socket.IO in React, you must handle connection issues gracefully. Common problems include network loss—such as a user losing Wi-Fi or switching networks—and server downtime, which can interrupt the connection between your app and the server.

Socket.IO is designed to address these issues automatically:

• If the connection drops, Socket.IO will attempt to reconnect using an exponential backoff strategy;
• It waits for a short time before the first reconnection attempt, then gradually increases the wait time between subsequent attempts, reducing unnecessary network traffic and server load;
• Socket.IO emits specific events such as connect_error, reconnect_attempt, and reconnect_failed that you can listen for in your React components.

By monitoring these events, you can inform users about the current connection status and take appropriate action when errors occur.

To enhance user experience, you should display connection status and error messages in your React UI. For example, you can use a component or banner to show when the app is trying to reconnect, when it has reconnected, or if it has failed to reconnect after several attempts. Listening to Socket.IO events in your components lets you update state variables that control these UI elements. This approach ensures users are always aware of the application's real-time connectivity, helping to build trust and reduce confusion during network interruptions.

Strategies for displaying connection status:

• Show a banner or notification when reconnecting;
• Update the UI to indicate successful reconnection;
• Display a clear error message if reconnection fails after several attempts.

By responding to Socket.IO events such as "connect_error", "reconnect_attempt", and "reconnect_failed", you can keep users informed about what is happening behind the scenes.

import { useEffect, useState } from "react";
import { useSocket } from "./SocketProvider";

function ConnectionStatus() {
  const socket = useSocket();
  const [status, setStatus] = useState("connected");

  useEffect(() => {
    if (!socket) return;

    const handleConnect = () => setStatus("connected");
    const handleConnectError = () => setStatus("error");
    const handleReconnectAttempt = () => setStatus("reconnecting");
    const handleReconnectFailed = () => setStatus("failed");

    socket.on("connect", handleConnect);
    socket.on("connect_error", handleConnectError);
    socket.on("reconnect_attempt", handleReconnectAttempt);
    socket.on("reconnect_failed", handleReconnectFailed);

    return () => {
      socket.off("connect", handleConnect);
      socket.off("connect_error", handleConnectError);
      socket.off("reconnect_attempt", handleReconnectAttempt);
      socket.off("reconnect_failed", handleReconnectFailed);
    };
  }, [socket]);

  return (
    <div>
      {status === "connected" && <p>🟢 Connected</p>}
      {status === "reconnecting" && <p>🟡 Reconnecting…</p>}
      {status === "error" && <p>🔴 Connection error</p>}
      {status === "failed" && <p>❌ Unable to reconnect</p>}
    </div>
  );
}