How to Build a Real-Time Application
Add real-time features to your web app with WebSockets, Server-Sent Events, or Supabase Realtime.
What You'll Learn
This intermediate-level guide walks you through how to build a real-time application step by step. Estimated time: 14 min.
Step 1: Choose your real-time technology
Select WebSockets for bidirectional communication, SSE for server-to-client, or Supabase Realtime for database changes.
Step 2: Set up the server
Configure your WebSocket server or SSE endpoint with proper connection management and authentication.
Step 3: Build the client
Implement client-side connection handling with auto-reconnection, buffering, and state synchronization.
Step 4: Handle scaling
Plan for horizontal scaling with Redis pub/sub or managed WebSocket services for production traffic.
Step 5: Test reliability
Test connection drops, high message volumes, and concurrent user scenarios to ensure reliability.
Frequently Asked Questions
WebSockets or Server-Sent Events?▾
Use SSE for simple server-to-client updates like notifications. Use WebSockets when you need bidirectional real-time communication.
How do I scale WebSocket connections?▾
Use Redis pub/sub to coordinate between server instances, or managed services like Pusher or Ably that handle scaling automatically.
What about Supabase Realtime?▾
Supabase Realtime is excellent for real-time database change notifications. It's the simplest option if you're already using Supabase.