Supabase Realtime

Real-time data synchronization service for web and mobile apps, delivering low-latency updates over WebSockets. Supports three core modes: Broadcast for sending messages between clients, Presence for tracking and syncing user state across sessions, and Postgres Changes for listening to database inserts, updates, and deletes as they happen.

Supabase Realtime is open source and globally distributed, with client libraries for JavaScript, Dart, Swift, and Kotlin. It integrates directly with Supabase auth and Row Level Security so channel access can be controlled per user. Unlike generic WebSocket services, it combines broadcast messaging, presence tracking, and database change streams in one stack, making it suited for apps that need real-time UI updates driven by database changes or peer-to-peer events.

Core features:

• Broadcast channels for low-latency messaging via client libraries, REST, or database triggers
• Presence for tracking who is online and syncing user state across connected clients
• Postgres Changes for real-time subscription to table inserts, updates, and deletes
• Row Level Security and auth integration for channel access control
• Multiple client SDKs including JavaScript, Dart, Swift, and Kotlin

Common applications include chat with typing indicators and presence, collaborative document editing and whiteboards, live dashboards for data visualization, multiplayer games with shared state, and social features such as live reactions and activity feeds. Developers subscribe to channels with filters on schema, table, and event type, then receive updates over WebSockets without polling.